¶ 151. 0dissenting). This is an ,action challenging the constitutionality of Wis. Stat. § 40.02(20), which defines the term "dependent" in Chapter 40 of the Wisconsin Statutes relating to the Public Employee Trust Fund. It also challenges the constitutionality of Wis. Stat. § 103.10(3)(b)3., which defines the persons with a serious health condition for whom an employee may take family leave under Wis. Stat. § 103.10, Wisconsin's Family and Medical Leave Act.
¶ 152. In their complaint, the plaintiffs describe themselves as six "lesbian couples in committed, intimate relationships." They set out a series of health-related hardships that they believe would be alleviated if they were able to obtain certain health care benefits from the state. Although each couple includes a current or former state employee, none of these employees is eligible to obtain for her domestic partner family health benefits that are available to state employees who are married to an opposite-sex spouse. In sum, the plaintiffs seek access to the same health insurance and family leave options that the state offers to employees in a traditional marriage.
¶ 153. The plaintiffs' action is sweeping and significant. It is part of the American Civil Liberties Union's (ACLU) National Lesbian and Gay Rights Project. It presents a major civil rights issue that could affect every public employer that operates under the Public Em*71ployee Trust Fund and, potentially, every employer governed by Wisconsin's Family and Medical Leave Act.
¶ 154. This phase of the action does not address the merits of the suit. It is confined to the procedural question whether eight "municipalities" — two cities, two villages, two towns, and two school districts — may intervene in the suit as parties. The majority denies the municipalities the right to intervene. Its crimped legal analysis treats the municipalities' request as though the case involved nothing more than a routine zoning variance instead of one of the great social and political controversies of our time.
¶ 155. The majority opinion brings to mind the lament of former United States Congressman and United States Court of Appeals Judge Abner Mikva about the United States Supreme Court's decision in Roe v. Wade, 410 U.S. 113 (1973). In 1999 Judge Mikva told an interviewer that he supported the result in Roe v. Wade but regretted that the Supreme Court had "preempted the whole political process," which he believed was moving legislatively toward greater abortion rights. The Court's decision "pleased a lot of us," Mikva said, "[b]ut it angered [the] minority with a passion, because they had just been short-circuited in their efforts to fight it out in the political arena." Mikva continued:
You can't write a justice of the Supreme Court and say 'Vote No." You can't even picket at the Supreme Court, though they tried to. There is a frustration that these five or six people, unelected, had made this basic decision which had been the subject of political process for so many years before. The justices were surprised. The late justice Blackm[u]n expressed his shock at how angry the minority was with the decision. I could have told him that was going to happen. And in retrospect, I wish the [C]ourt had stayed its hand and allowed the *72political process to continue, because we would have legislated the effect of Roe v. Wade in most states — not all of them, but in most states — and we wouldn't have had to pay the political price we've had to pay for it being a court decision. The people who are angry at that . court are angry beyond measure. As far as they are concerned, the whole system is rotten because they've lost their opportunity to slug it out.1
¶ 156. Once again, this phase of the action does not address the merits of the suit. However, the effect of the majority decision is to deprive eight representative municipalities of the opportunity to slug it out in the process leading to an ultimate decision. As a result, they will have no real say about their future ability to determine whether to extend dependent health care benefits to same-sex couples, as some municipalities voluntarily have. The decision to exclude the municipalities is not good for the Wisconsin judiciary, and it is not good law. As a result, I must respectfully dissent.
I — I
¶ 157. The principal legal issue before the court is whether the municipalities satisfy the requirements of Wis. Stat. § 803.09(1) to intervene in this suit as a matter of right. Wisconsin Stat. § 803.09(1) reads as follows:
Upon timely motion anyone shall be permitted to intervene in an action when the movant claims an interest relating to the property or transaction which is *73the subject of the action and the movant is so situated that the disposition of the action may as a practical matter impair or impede the movant's ability to protect that interest, unless the movant's interest is adequately represented by existing parties.
¶ 158. With the exception of one word, the quoted language is identical to the rule adopted by this court in 1975 as part of the new Wisconsin Rules of Civil Procedure.2 See 67 Wis. 2d 585, 650-51 (1975).
¶ 159. Subsection (1) is based on Rule 24(a) of the Federal Rules of Civil Procedure. Charles D. Clausen and David E Lowe, The New Wisconsin Rules of Civil Procedure Chapters 801-803, 59 Marq. L. Rev. 1, 108 (1976) (hereinafter Clausen). Accordingly, "we look to cases and commentary relating to Rule 24(a)(2) for guidance in interpreting sec. 803.09(1)." State ex rel. Bilder v. Twp. of Delavan, 112 Wis. 2d 539, 547, 334 N.W.2d 252 (1983).
¶ 160. Federal Rule 24 evolved significantly from its inception in 1937. A 1946 amendment provided that upon timely application anyone shall be permitted to intervene "(3) when the applicant is so situated as to be adversely affected by ... disposition of property which is in the custody or subject to the control or disposition of the court or officer thereof." Federal Rule of Civil Procedure 24(a)(3) (1946). This language amplified and restated federal practice. See Cascade Natural Gas Corp. v. El Paso Natural Gas Co., 386 U.S. 129, 134 (1967). However, the rule was altered in 1966 to facilitate substantially expanded intervention as of right. This revised rule, which drew upon federal civil rules related to joinder of persons needed for just adjudication (Rule 19) and class actions (Rule 23), provides that an appli*74cant is entitled to intervene in an action when the applicant's position is comparable to that of a person under Rule 19(a) (2) (i), unless the movant's interest is already adequately represented in the action.3 See Advisory Committee Notes, 1966 Amendment, 28 U.S.C.A., Rule 24 at 755-57.
¶ 161. Intervention, as a procedural mechanism under Rule 24, is to be construed liberally, and doubts resolved in favor of the proposed intervenor. See 6 James William Moore, et al., Moore's Federal Practice § 24.03[l][a], at 24-24, 24-25 (3d ed. 2002)(hereinafter Moore); Southwest Center for Biological Diversity v. Berg, 268 F.3d 810, 818 (9th Cir. 2001); Stupak-Thrall v. Glickman, 226 F.3d 467, 472 (6th Cir. 2000); Purnell v. City of Akron, 925 F.2d 941, 950 (6th Cir. 1991); United States v. Stringfellow, 783 F.2d 821, 826 (9th Cir. 1986). Some federal courts have stated that the requirements for intervention are to be construed in favor of intervention. Am. Maritime Transp., Inc. v. United States, 870 F.2d 1559, 1561 (Fed. Cir. 1989) ("the requirements for intervention are to be construed in favor of intervention"); Westlands Water Dist. v. United States, 700 F.2d 561, 563 (9th Cir. 1983) ("we recognize that the requirements of Rule 24(a) are to be construed in favor of the applicant for intervention") (citation omitted).
*75¶ 162. Under Federal Rule 24, the intervention inquiry must be flexible, involving a balancing and blending of requirements, often applying them as a group. Moore, supra, § 24.03[l][a], at 24-25. Intervention as of right may be granted if the applicant's claimed interest may be significantly impaired by the action, even if some uncertainty exists regarding that interest. Id.
II
¶ 163. Wisconsin's adoption of Federal Rule 24(a)(2) in Wis. Stat. § 803.09(1) was a departure from our prior law — namely, Wis. Stat. § 260.205 (1973)— because intervention under the prior statute "was only permissive, i.e., permitted in the court's discretion." Clausen, supra, at 108. Professor Clausen observed:
While the intervention under subsection (1) is of right ("shall be permitted"), the rule is still discretionary insofar as the court must make a determination as to [1] whether or not the motion is timely, [2] whether the absent party's ability to protect his interest may as a practical matter be impaired, and [3] whether the absent party's interest is adequately represented by existing parties.
Id.
¶ 164. Clausen's discussion of circuit court "discretion" in making certain determinations under our rule is somewhat at odds with recent pronouncements in federal cases. For instance, in the Southwest Center case, the court said: "Rule 24 provides for intervention as of right and permissive intervention. . . . We review de novo a district court's denial of a motion to intervene as of right, with the exception of timeliness, which we *76review for abuse of discretion." Southwest Center, 268 F.3d at 817 (emphasis added). See also United States v. BDO Seidman, 337 F.3d 802, 808 (7th Cir. 2003) ("This court reviews the [intervention] factors de novo, with the exception of the first factor — the timeliness of the intervention — which this court reviews for an abuse of discretion."); Stupak-Thrall, 226 F.3d at 471 ("We review a district court's decision regarding timeliness (the first element) for abuse of discretion; the remaining three elements are reviewed de novo."). What these courts are saying is that three of the four factors are deemed questions of law.
¶ 165. Analytically, the more discretion this court gives to our circuit courts to deny motions for intervention as of right, the more we revert to our prior law in which there was no intervention "as of right."
¶ 166. Immediately after the Clausen discussion quoted in ¶ 163, herein, Professor Clausen added: "Nevertheless, the new rule is founded upon the same considerations underlying section 803.03 which define those parties who must be joined in an action if feasible." Clausen, supra, at 108; see also City of Madison v. WERC, 2000 WI 39, ¶ 11 n.8, 234 Wis. 2d 550, 610 N.W.2d 94. Thus, Wis. Stat. § 803.03 is pertinent to our review. It reads in part:
Joinder of persons needed for just and complete adjudication.
(1) Persons to be joined if feasible. A person who is subject to service of process shall be joined as a party in the action if:
(a) In the person's absence complete relief cannot be accorded among those already parties; or
(b) The person claims an interest relating to the *77subject of the action and is so situated that the disposition of the action in the person's absence may:
1. As a practical matter impair or impede the person's ability to protect that interest. (Emphasis added.)
In my view, the words in the title of § 803.03 — "just and complete adjudication" — suggest the spirit in which the section ought to be interpreted. See, e.g., Zabel v. Zabel, 210 Wis. 2d 336, 343, 565 N.W.2d 240 (Ct. App. 1997) (concluding that the joinder of a husband's mother as a third-party defendant in a divorce action was necessary for a just and complete adjudication of the parties' martial property rights).
¶ 167. The present case, of course, is a civil lights action. Plaintiffs candidly acknowledge that their suit is intended to have wide impact. Although the named plaintiffs include only six same-sex couples, their suit is intended to affect all same-sex couples in state service. It is reasonable to suppose that they also intend a favorable decision to affect same-sex couples who work for Wisconsin counties, cities, villages, towns, and school districts . . . and thus, by necessity, their employers. The fact that the plaintiffs have chosen strategically not to include in this suit any same-sex couples from Wisconsin local governments4 should not preclude representative municipalities from weighing in for a *78"just and complete adjudication" of the controversy because, as "a practical matter," a decision for the plaintiffs will "impair or impede" the municipalities' ability to protect their interests. As "a practical matter," this suit is equivalent to a class action.
b — I HH H-f
¶ 168. As noted above, Wis. Stat. § 803.09(1) has multiple elements and requires interpretation. The first major case interpreting the rule was Bilder in 1983. The court declared that the Wisconsin intervention rule establishes a four-part test that the proposed intervenor must meet:
(1) timely application for intervention;
(2) an interest relating to the property or transaction which is the subject of the action;
(3) that the disposition of the action may as a practical matter impair or impede the proposed intervenor's ability to protect that interest; and
(4) that the proposed intervenor's interest is not adequately represented by existing parties.
Bilder, 112 Wis. 2d at 545.
¶ 169. In a second major case involving intervention, this court summarized the four-part test as follows:
(1) that the motion to intervene be made in a timely fashion;
(2) that the movant claims an interest relating to the property or transaction which is the subject of the action;
*79(3) that the movant is so situated that the disposition of the action may as a practical matter impair or impede the movant's ability to protect that interest; and
(4) that the movant's interest is not adequately represented by existing parties.
Armada Broad, Inc. v. Stirn, 183 Wis. 2d 463, 471, 516 N.W.2d 357 (1994).
¶ 170. These two decisions either paraphrase or repeat the exact language of the rule. The same may be said of City of Madison v. WERC, 234 Wis. 2d 550, ¶ 11, and Wolff v. Town of Jamestown, 229 Wis. 2d 738, 740-41, 601 N.W.2d 301 (Ct. App. 1999). However, the majority opinion supplements the language of our rule and the formulations in previous opinions by adding a new word to the element relating to the intervenor's claimed interest. The majority rephrases the "interest" test to read: "that the movant claims an interest sufficiently related to the subject of the action[.]" Majority op., ¶ 38 (emphasis added).
¶ 171. This subtle change is not insignificant. Its effect is to vest courts with discretion to determine whether a potential intervenor's "interest" is "sufficient" to satisfy the second prong of the rale. The "interest" element or test of the rule happens to be the only element that Professor Clausen did not mention as involving some judicial discretion. See ¶ 163, herein.
¶ 172. Although the majority opinion ultimately concedes that the municipalities satisfy the "interest" element, it uses its new formulation of the test to attack the interest claimed, so that it can conclude: "The municipalities' generalized interest in the subject of the instant action, namely, the constitutionality of a statute *80applicable to a plan for state employees, is at the far edge of what may constitute a sufficiently related interest for purposes of the right to intervene statute." Majority op., ¶ 74 (emphasis added). The majority opinion then applies the coup de grace: "The weakness of the municipalities' showing with respect to the interest requirement means that to demonstrate a right of intervention the municipalities should make a strong showing in the other requirements to intervene as of right." Id. In other words, it is not enough for a potential intervenor to satisfy all four elements or tests for intervention as of right; now, a potential intervenor must "strongly" satisfy these elements, or it may not be permitted to intervene as of right.
IV
¶ 173. The first element of the rule is timely application for intervention. There is no dispute that the municipalities' motion for intervention was timely. Consequently, the first element of the rule is satisfied.
V
¶ 174. The second element of the rule is interest, namely, whether the municipalities' claim an interest relating to the property or transaction which is the subject of the action.
¶ 175. In Bilder, like Armada, City of Madison, and Wolff, the court approved intervention. The decision in Bilder turned on the intervenor's "interest." See Bilder, 112 Wis. 2d at 549-50. The court's discussion admittedly uses the word "sufficient" in several places, but the spirit of the discussion is quite different from what we see in the majority opinion. The Bilder court said:
*81The federal courts and commentators have not been able to derive a precise test for determining which type of interest is sufficient to allow a party to intervene as a matter of right.
The various federal courts have differed in their approaches. Some appear to verbalize the sufficiency of interest factor as in part a question of standing of as requiring a "direct, substantial, legally protectable interest in the proceedings."
Other courts have viewed the interest test for intervention more broadly.
We agree with the broader, pragmatic approach to intervention as of right. In deciding whether to allow a party to intervene as a matter of right, the court should view the interest sufficient to allow the intervention practically rather than technically.
Courts using the pragmatic, policy-based approach [ ] view the interest test as "primarily a practical guide to disposing of lawsuits by involving as many apparently concerned persons as is compatible with efficiency and due process." Nuesse v. Camp, 385 F.2d 694, 700 (D.C. Cir. 1967).
Bilder, 112 Wis. 2d at 547-49 (internal citations omitted) (emphasis added).
¶ 176. The Bilder court then quoted with approval a passage from Smuck v. Hobson, 408 F.2d 175, 179-80 (D.C. Cir. 1969):
The decision whether intervention of right is warranted thus involves an accommodation between two *82potentially conflicting goals: to achieve judicial economies of scale by resolving related issues in a single lawsuit, and to prevent the single lawsuit from becoming fruitlessly complex or unending. Since this task will depend upon the contours of the particular controversy, general rules and past decisions cannot provide uniformly dependable guides.... [T]he [interest] requirement should be viewed as a prerequisite rather than relied upon as a determinative criterion for intervention. If barriers are needed to limit extension of the right to intervene, the criteria of practical harm to the applicant and the adequacy of representation by others are better suited to the task. If those requirements are met, the nature of his "interest" may play a role in determining the sort of intervention which should be allowed— whether, for example, he should be permitted to contest all issues, and whether he should enjoy all the prerogatives of a party litigant.
Bilder, 112 Wis. 2d at 549 (emphasis added).
¶ 177. In Chief Judge David Bazelon's view, the interest requirement should not be used as the determinative criterion for intervention as of right. "It would be unfortunate," he said, "to allow inquiry to be led once again astray by a myopic fixation upon 'interest.'" Smuck, 408 F.2d at 179.
¶ 178. Here, the majority opinion devotes 28 paragraphs to discrediting the municipalities' interest. The reason for this laborious effort is revealed in ¶ 39 of the opinion, where the majority admits that "a movant's strong showing with respect to one requirement may contribute to the movant's ability to meet other requirements as well." Majority op., ¶ 39 (citing Moore, supra, § 24.03[l][b], at 24-25 ("[A] lesser showing of impairment may be required by the court if the applicant's interest is very strong....")). The majority *83portrays the municipalities' interest as "weak" so that it can characterize the "interest" element as dragging down the municipalities' position on the other three elements. See majority op., ¶ 74.
¶ 179. What is the municipalities' interest?
¶ 180. According to Wis. Stat. § 40.01(a), the Public Employee Trust Fund was created to aid public employees in protecting themselves and their beneficiaries against the financial hardships of old age, disability, death, illness, and accident. The trust fund includes multiple programs, such as the retirement system and health care coverage, that make provision for these concerns.
¶ 181. The Wisconsin Retirement System (WRS) is one of the largest in the United States. Any public employer in Wisconsin may elect to participate in the WRS, Wis. Stat. § 40.21, but for some employers — such as the state and all counties except Milwaukee County —participation is mandatory. Art Zimmerman, Wisconsin Retirement System Informational Paper 78, Wisconsin Legislative Fiscal Bureau 8 (January 2007). The Fiscal Bureau reports that a total of 1,412 public employers, including 58 state agencies, participate in the WRS. Other participants in the WRS include 71 counties, 186 cities, 218 towns, 236 villages, and 426 school districts. Zimmerman, supra, at 9. This listing includes the eight municipalities seeking to intervene in this case.
¶ 182. For purposes of this suit, it is clear that not nearly as many local public employers participate in the Department of Employee Trust Funds (DETF) health insurance programs as in the WRS. The exact number of local employers who participate is not known to the writer. Nonetheless, according to the DETF's Comprehensive Annual Financial Report for 2004, 11,669 "ac*84tive" local employees and 1,787 retired local employees participated in a health insurance program through the fund in 2004. This figure includes employees from the city of Watertown, village of Oostburg, and town of Cottage Grove whose employers seek to intervene in this suit.
¶ 183. Wisconsin Stat. § 40.02(20) defines the word "dependent" for use throughout Chapter 40, except for Wis. Stat. § 40.98. Subsection (20) reads:
(20) "Dependent" means the spouse, minor child, including stepchildren of the current marriage dependent on the employee for support and maintenance, or child of any age, including stepchildren of the current marriage, if handicapped to an extent requiring continued dependence. For group insurance purposes only, the department may promulgate rules with a different definition of "dependent" than the one otherwise provided in this subsection for each group insurance plan.
¶ 184. The word "dependent," as defined in Wis. Stat. § 40.02(20), appears in Wis. Stat. § 40.03(6)(b) (granting the Group Insurance Board the power to provide employees and their dependents with group insurance plans), § 40.04(10) (providing for an accumulated sick leave conversion account for retired employees and their surviving dependents), § 40.04(11) (providing for a health insurance premium credit account for retired employees and their surviving dependents), §§ 40.05(b), (be), and (be), (providing for unused sick leave to be credited to payment of health insurance premiums for employees and their surviving insured dependents), § 40.51(3) (providing that health insurance contracts shall establish provisions for employees and dependents to continue group coverage), § 40.52(l)(a) (providing for a "family coverage option" to allow coverage for all eligible dependents), § 40.52(2) *85(allowing for special insurance plan provisions when one spouse or other dependent is eligible for federal health and hospital care for the aged), § 40.80(2r)(a)2. (defining "domestic relations order," taking into consideration a court's decision to assign deferred compensation assets to "a spouse, former spouse, child, or other dependent"), and §§ 40.95(l)(a) and (2) (providing that the DETF administer a program to provide credits for the purchase of health insurance for retired employees and their surviving insured dependents).
¶ 185. Thus, a court decision altering the interpretation of the word "dependent" is likely to have wide effect on local participants in a number of programs in Chapter 40. Some of these effects will be clear and direct; others will be unclear and indirect. If there were an evidentiaiy record in this suit, the uncertainty about the effects of a decision favoring the plaintiffs would be reduced.
¶ 186. Watertown, Oostburg, and Cottage Grove are enrolled in the specific DETF plans that the plaintiffs seek to modify. Thus, these three municipalities — and all other municipalities similarly situated — will experience the direct costs of any court decision mandating that DETF plans cover a same-sex domestic partner and the children of a same-sex domestic partner when those children are dependent upon the employee-partner for support and maintenance. The remaining five municipalities — Caledonia, Green Bay, Hobart, the School Board of New Berlin, and Raymond School District #14, and all municipalities similarly situated— would likely confront more expensive health care coverage if they wanted to join a DETF health care plan, or if they were required to join a DETF health care plan.
¶ 187. Watertown, Oostburg, and Cottage Grove have collective bargaining agreements. Court-ordered *86coverage of same-sex domestic partners would rewrite these collective bargaining agreements by mandating benefits that were not negotiated at the bargaining table. These new benefits would be provided in addition to, not in beu of, previously negotiated benefits, adding to the cost of fringe benefits. The spillover of a decision favoring the plaintiffs to the collective bargaining agreements of other municipalities — through arbitration or legal action, as well as negotiation — would be certain if not direct.
¶ 188. The eight municipalities here claim that every municipality that is part of any DETF program employing the term "dependent," as defined in Wis. Stat. § 40.02(20), will be directly affected by any change in the interpretation of this definition.5 This includes all programs and subjects enumerated in ¶¶ 181-82 above, including deferred compensation programs and qualified domestic relations orders (QDRO). They contend persuasively that "[t]he Wisconsin [CJonstitution is not so facile that it requires redefining 'spouse' in one DETF program, but completely disregards the very same effect in another [program]."
¶ 189. The municipalities posit additional interests that are less tangible than increased costs and modification of existing contracts. They contend that a *87judicial decision favoring the plaintiffs would constitute an incursion into their core powers to govern their own affairs. In our system of government, municipalities have the power to hire employees and negotiate individual contracts or collective bargaining agreements with these employees.6 These negotiations involve tradeoffs. Because their revenues are limited, local governments are seldom in a position to afford all the compensation and benefits that local employees would like. Thus, the granting of one benefit often comes at the expense of another and may affect overall compensation. When a new benefit is imposed upon local governments from the outside, it strips these governments of their authority to negotiate or perhaps even plan for the new benefit.
¶ 190. Of course, the legislature may impose controversial or unwanted benefit obligations upon local governments and thereby affect their costs and existing contracts. However, legislatively created benefits represent the fruit of a political process in which local governments freely and actively participate. Legislatively imposed benefit obligations can be given a delayed effective date or be softened by increased state aid, as political accommodations. Legislatively imposed benefits can also be repealed at a later date. By contrast, benefits ordered by a court interpreting the *88Wisconsin Constitution do not permit political accommodations. They are simply ordered. If the change involved is not only costly but also unpopular, it will understandably be perceived as denying local governments the power to control their own destiny.
¶ 191. It can be argued that courts exist for the very purpose of vindicating "rights" that might otherwise be disregarded by political majorities. But courts undermine their legitimacy in making calls that antagonize majority opinion when they slam the door on a full airing of facts and views. The municipalities here are representative of many other local governments in Wisconsin whose interests should be fully considered.
VI
¶ 192. The third element of the rule is impairment of interest. The essence of this element is that the movant's interest may as a practical matter be impaired if the movant is not allowed to protect it by participating in the suit.
¶ 193. It is clear that a decision on the merits in the plaintiffs' favor would immediately impair the rights of Cottage Grove, Watertown, and Oostburg because these municipalities are currently enrolled in DETF health care plans. The court of appeals reached the same conclusion, Helgeland v. Wisconsin Municipalities, 2006 WI App 216, ¶ 19, 296 Wis. 2d 880, 724 N.W.2d 208, but the majority inexplicably does not. The majority concludes that, since the municipalities are not parties to any contract at issue in the present litigation, the municipalities' interest "cannot be directly impaired by Helgeland's action." Majority op., ¶ 75. The majority's conclusion cannot be correct. The three municipalities are part of DETF plans that would *89be directly affected by a ruling favoring the plaintiffs. As a result, their financial interests would be impaired in a direct and immediate fashion. If we do not know in more detail the financial effect on the three municipalities, we can attribute that deficiency to an underdeveloped record caused by the involuntary absence of the municipalities as intervenors.
¶ 194. The municipalities also couch the impairment of interest element in terms of the negative effect of stare decisis on all eight movants if the plaintiffs were to prevail on the merits. The majority acknowledges the adverse effect that stare decisis might have on the municipalities, but it describes this impact as generic, that is, "essentially the same effect that any employer might claim when an action before the court threatens to increase costs that the employer is obligated to pay ...". Majority op., ¶ 84 (emphasis added). This comment unduly downplays the effects of a possible constitutional ruling on future litigation.
¶ 195. Black's Law Dictionary defines "stare deci-sis" as "[t]he doctrine of precedent, under which it is necessary for a court to follow earlier judicial decisions when the same points arise again in litigation." Black's Law Dictionary 1414 (7th ed. 1999). Under the doctrine of stare decisis, a legal precedent is established when a court expressly decides a specific issue of law.7 Moore, supra, § 24.03[3][b], at 24 — 42.2. Thus, an intervenor's interest can be impaired, as a practical matter, if a *90pending action will cause a stare decisis impact that is harmful to the applicant. Id.
¶ 196. Federal courts have analyzed the impact of stare decisis in different ways. The majority cites Bethune Plaza Inc. v. Lumpkin, 863 F.2d 525, 533 (7th Cir. 1998), for the proposition that stare decisis should establish a Rule 24(a)(2) impairment "infrequently," and it cites authority for the notion that stare decisis is merely "an important consideration." Majority op., ¶ 78, ¶ 78 n.69 (citing United States v. State of Oregon, 839 F.2d 635, 638 (9th Cir. 1988)). However, other federal courts have found the impact of stare decisis to be a determinative factor. See Stone v. First Union Corp., 371 F.3d 1305, 1309-10 (11th Cir. 2004) (noting that "the potential for a negative stare decisis effect 'may supply that practical disadvantage which warrants intervention of right'"); Coal. of Arizona/New Mexico Counties for Stable Econ. Growth v. Dept. of Interior, 100 F.3d 837, 844 (10th Cir. 1996) (recognizing that "the stare decisis effect of the district court's judgment is sufficient impairment for intervention under Rule 24(a)(2)"); Anderson Columbia Envtl., Inc. v. United States, 42 Fed. Cl. 880, 882 (1999) ("The potential stare decisis effect of a decision often supplies the 'practical impairment' required by Rule 24(a).").
¶ 197. There are several reasons why stare decisis is a weighty factor in this case. In 1992 the court of appeals rejected a discrimination and equal protection claim based on facts similar to the present suit. Phillips v. Wis. Pers. Comm'n, 167 Wis. 2d 205, 482 N.W.2d 121 (Ct. App. 1992). The Phillips decision has served as the controlling precedent in Wisconsin for 15 years. It continues to bind the court of appeals and circuit courts. See Cook v. Cook, 208 Wis. 2d 166, 560 N.W.2d 246 (1997). Any decision overruling Phillips will re*91quire action by this court. If this court were to overrule Phillips, the new decision would bind Wisconsin courts just as Phillips has bound Wisconsin courts; and if this court's decision were based on the Wisconsin Constitution, as plaintiffs request, even the legislature could not change the law without first securing an amendment to the Wisconsin Constitution. Thus, the municipalities have a vital interest in shaping the record that will be presented to this court. To do so, they must intervene. If the municipalities are denied the right to intervene in the circuit court, they are less likely to gain intervenor status at the appellate level and will lose any right to shape the record.
¶ 198. The import of stare decisis is neatly presented by novel issues of statutory construction, Moore, supra, § 24.03[3][b], at 24-42.2, and this suit is a classic example. Negative stare decisis would impede the municipalities' efforts if they chose to assert their interest separately in future litigation, as the controlling construction of the word "dependent" in Wis. Stat. § 40.02(20) would effectively foreclose their position. Courts are not going to construe the statutory term "dependent" to have different meanings in municipal and state beneficiary contexts.
¶ 199. In short, there are both direct financial impacts and likely stare decisis impacts potentially at play in this case, and these effects satisfy the impairment of interest requirement.
VII
¶ 200. The fourth and final requirement for intervention as of right is that the movant's interest is not adequately represented by existing parties.
¶ 201. The United States Supreme Court has stated that the adequate representation requirement "is *92satisfied if the applicant shows that the representation of his interest 'may be' inadequate" and "the burden of making that showing should be treated as minimal." Trbovich v. United Mine Workers of America, 404 U.S. 528, 538 n.10 (1972) (citing 3B J. Moore, Federal Practice 24.09-1 (4) (1969)) (emphasis added). "[P]ro-posed intervenors need show only that there is a potential for inadequate representation" to satisfy this requirement. Grutter v. Bollinger, 188 F.3d 394, 400 (6th Cir. 1999). Accordingly, the key inquiry for this requirement is whether an existing party may not adequately represent the interest of a proposed inter-venor, not whether an existing party will not adequately represent that interest. In this regard, it may be enough to show that the existing party will not make all the arguments that the proposed intervenor would make. See Michigan State AFL-CIO v. Miller, 103 F.3d 1240, 1247 (6th Cir. 1997) ("For example, it may be enough to show that the existing party who purports to seek the same outcome will not make all of the prospective intervenor's arguments.").
¶ 202. In 1994 this court listed several factors for evaluating adequacy of representation. The court said it looked to see (1) whether there is a showing of collusion between the existing "representative" party and the opposing party; (2) whether the representative party's interest is adverse to that of the proposed intervenor; or (3) whether the representative party has failed in the fulfillment of its duty. Armada, 183 Wis. 2d at 476 (citing Sewerage Comm'n of City of Milwaukee v. State DNR, 104 Wis. 2d 182, 189, 311 N.W.2d 677 (Ct. App. 1981)). The court also repeated the statement from Trbovich that the showing required should be treated as "minimal." Id. (quoting Trbovich, 404 U.S. at 538 n.10).
*93¶ 203. Although the court's three criteria, properly interpreted, do not create an especially difficult hurdle to intervention, these criteria are not meant to be exhaustive.8 There may be a variety of additional circumstances that suggest that representation by an existing party is inadequate. See Daggett v. Comm'n on Governmental Ethics & Election Practices, 172 F.3d 104, 111 (1st Cir. 1999) (observing that the trilogy — "adversity of interest, collusion or nonfeasance" — may not have been intended to be an exclusive list). Demonstrating that a movant's interest is different in kind or degree from that of a named party may suffice to establish inadequacy of representation. B. Fernandez & Hnos., Inc. v. Kellogg USA, Inc., 440 F.3d 541, 544-47 (1st Cir. 2006).
¶ 204. Diversity of interest can be the conclusive factor when evaluating the adequacy of representation. As the Wright treatise notes, "[t]he most important factor in determining adequacy of representation is how the interest of the absentee compares with the interests of the present parties. If the interest of the absentee is not represented at all, or if all existing parties are adverse to the absentee, then there is no adequate representation." 7C Charles Alan Wright et al., Federal Practice and Procedure: Civil 3d § 1909, at 393-94 (2007) (footnotes omitted) (emphasis added) (hereinafter Wright). Significantly, the treatise goes on to state:
If there is a significant difference between the interest of the absentee and that of the party, there is a risk that the party will not provide adequate representation of *94the interest of the absentee. A discriminating appraisal of the circumstances of the particular case is required. Since the rule is satisfied if there is a serious possibility that the representation may be inadequate, all reasonable doubts should be resolved in favor of allowing the absentee, who has an interest different from that of any existing party, to intervene so that the absentee may be heard in his own behalf.
Id. at 440 (emphasis added).
¶ 205. Diversity of interest tips the balance toward granting intervention in this case. DETF and the municipalities have different functions. DETF administers benefit plans for public employees. It is an agency of state government; it is not a separate government entity. By contrast, cities, villages, towns, and school districts are separate governments. Although they must operate within "limits" imposed by state law, these governments set their own budgets and make their own policy. The limits include revenue limits for public schools (Wis. Stat. § 121.91), and levy limits for cities, villages, and towns (Wis. Stat. § 66.0602). These limits distinguish the municipalities from the state, which has much greater latitude than local governments in taxing and spending. These limits implicate a different eviden-tiary record than the record that might serve the state's exclusive interest.
¶ 206. Given the difference in their status, the municipalities question the strategy the Attorney General has employed to defend the constitutionality of Wis. Stat. § 40.02(20), i.e., the strategy of opposing discovery and moving for judgment on the pleadings. The State's strategy relies entirely on the continuing validity of Phillips, even though Phillips did not decide head-on some of the issues now presented by the plaintiffs.
*95¶ 207. Wright notes that "[a] mere difference of opinion concerning the tactics with which the litigation should be handled does not make inadequate the representation of those whose interests are identical with that of an existing party or who are formally represented in the lawsuit." Wright, supra, § 1909, at 431-36 (emphasis added).9 Fair enough. However, the interests of DETF and the municipalities are not identical, and the differences should not be dismissed using words like "attenuated" to shore up the analysis. See Majority op., ¶ 71.
¶ 208. In the court of appeals, Judge Charles Dyk-man observed in his concurrence/dissent that the approach of an attorney general is fundamentally different from that of private counsel hired to represent a client. See Helgeland, 296 Wis. 2d 880, ¶ 59 (Dykman, J., concurring in part, dissenting in part). Alluding to former Attorney General Peggy Lautenschlager, Judge Dykman stated: "The attorney general is required to defend the statute at issue, but how she does so and what issues she raises or does not raise are up to her. She determines how the case will be defended, for better or worse." Id. This is precisely the problem facing the municipalities and one that should not be summarily dismissed.
¶ 209. Judge Dykman added:
A good way to create mistrust is to deny participation in government. Of course, there is an endpoint to *96participation; lawsuits cannot be open to whoever wants to participate or only chaos wins. But here, the only factor keeping the municipalities from participation as a party is the majority's conclusion that, despite statements by the State's attorney which at least raise doubts, the statements do not amount to much. Perhaps they do not, but I believe that there is a reasonable perception that the attorney general has taken a position contrary to the one she advocates on the merits of this litigation.
Id., ¶ 61.
¶ 210. From the circuit court to the supreme court, Department of Justice attorneys have opposed intervention by the municipalities. A change in attorneys general has not altered the Department's position. If the State ultimately wins this case on the merits, its consistent opposition to the municipalities' intervention will be forgotten. But if the State loses the case, the State's opposition will be seen as hubris or collusion, and, in either event, a contributing factor to the defeat.
¶ 211. If intervention by the municipalities were likely to make this suit "fruitlessly complex or unending," Smuck, 408 F.2d at 179, denial of intervention would make sense. But denial of intervention here has prolonged the litigation, not shortened it, and has undermined the alleged urgency of the plaintiffs' circumstances. The municipalities' desire to develop a factual record establishing their particular financial and policy-setting interest cannot reasonably be described as weakening the State's position.
¶ 212. When this case returns to circuit court, the municipalities will have been kicked off the field and told they have the privilege of cheering for the State from the bleachers. As they prepare to wave their rally *97towels, they may note the irony of the plaintiffs' importing counsel from Illinois to explain Wisconsin civil procedure to Wisconsin courts, and of the American Civil Liberties Union seeking to vindicate diversity of lifestyles while successfully squashing diversity of views.
¶ 213. If the municipalities are disappointed by their remote seats, they will surely get over it once they accept the heartening "presumption" that the DETF adequately represents the municipalities' interest.
VIII
¶ 214. This is not a close case. The municipalities have satisfied all the tests under Wis. Stat. § 803.09(1) for intervention as of right. Because the majority holds otherwise, I respectfully dissent.
¶ 215. I am authorized to state that Justices PATIENCE DRAKE ROGGENSACK and ANNETTE KINGSLAND ZIEGLER join this dissent.
Interview by Harry Kreisler with Abner Jay Mikva, former United States Congressman, former United States Court of Appeals Judge for the D.C. Circuit, and former White House Counsel, in Berkeley, California (April 12, 1999) available at http://globetrotter.berkeley.edu/people/Mikva/mikva-con4.html (last visited Jan. 24, 2008) (emphasis added).
In the original rule, the word "he" was used in place of the word "movant" in the current phrase "the movant is so situated."
Federal Rule of Civil Procedure 24(a) currently reads:
(a) Intervention of Right. On timely motion, the court must permit anyone to intervene who:
(1) is given an unconditional right to intervene by a federal statute; or
(2) claims an interest relating to the property or transaction that is the subject of the action, and is so situated that disposing of the action may as a practical matter impair or impede the movant's ability to protect its interest, unless existing parties adequately represent that interest.
This suit is nearly identical to Alaska Civil Liberties Union v. State of Alaska & Municipality of Anchorage, 122 P.3d 781 (Alaska 2005), except that the Alaskan plaintiffs named the "Municipality of Anchorage" as a defendant, and Anchorage had its own representation in the case throughout. See also Baker v. State, 744 A.2d 864 (Vt. 1999) (action brought against state, city, town).
The plaintiffs' complaint seeks to change every DETF benefits plan. Under the heading "Relief Sought," the plaintiffs' first amended complaint asks the circuit court to:
C. Enter an order enjoining the defendants from excluding lesbian and gay male employees and their same-sex domestic partners from the same employment benefits provided to similarly-situated employees and their spouses, including by classifying same-sex domestic partners of state employees as dependents for purposes of participation in all employment benefit contracts and plans[.~\ (Emphasis added.)
The legislature has delegated general power to municipalities to hire personnel and negotiate employment contracts via Wis. Stat. § 111.70. See Glendale Prof'l Policemen's Ass'n v. City of Glendale, 83 Wis. 2d 90, 108, 264 N.W.2d 594 (1978) ("Sec. 111.70, Stats., is legislation that specifically authorizes local action, i.e., the adoption of collective bargaining agreements covering wages, hours, and conditions of employment even though statutes of statewide concern also govern wages, hours, and conditions of employment.").
The doctrine of stare decisis differs from that of res judicata, which involves a decision about a factual controversy rather than an issue of law. 6 James William Moore et al., Moore's Federal Practice § 24.03(3] [b], at 24-42.3 (3d ed. 2002). The 1966 amendment to Rule 24 eliminated the requirement that a mo-vant be legally bound by the outcome of the action. Id. at 24-42.4.
See 7C Charles Alan Wright et al., Federal Practice and Procedure: Civil 3d § 1909, at 393 (2007) ("The wide variety of cases that come to the courts make it unlikely that there are three and only three circumstances that would make representation inadequate and suggest that adequacy of representation is a very complex variable.").
The Wright treatise notes that when parties have identical interests mere differences of opinion regarding litigation tactics are not evidence of inadequate representation. See 7C Charles Alan Wright et al., Federal Practice and Procedure: Civil 3d § 1909, at 431-36 (2007). However, the treatise makes the important point, hy implication, that when parties' interests are not identical, a difference of opinion regarding strategy may be a factor to consider.