The issue in this case is whether a prior federal court judgment precludes a subsequent action in state court asserting state law claims omitted in the federal action. In particular, we must decide whether an independent school district is entitled to Eleventh Amendment immunity from suit in federal court such that the federal court would have lacked jurisdiction of the omitted state law claims. The court of appeals concluded that a school district is an arm of the state entitled to Eleventh Amendment immunity. 897 S.W.2d 879. Because we conclude that an independent school district is more like a county or city than it is like an arm of the state, and is amenable to suit in federal court, we hold that res judicata precludes litigation of the omitted state law claims in state court. We reverse the judgment of the court of appeals and render judgment for the independent school district and its board of trustees.
Charles McKinney was fired from his job as a band teacher with the San Antonio Independent School District (SAISD). McKinney, an African-American, contends that the termination was race-related. Consequently, he filed a race discrimination lawsuit in federal district court. While his federal lawsuit was pending, McKinney administratively appealed his termination to the Commissioner of Education of the Texas Education Agency, arguing that SAISD did not follow proper procedures in firing him. The Commissioner ruled in his favor, but the school district refused to reinstate McKinney.
While his administrative appeal was pending, McKinney told the federal court that he intended to amend his federal complaint “to present all his claims arising from the same facts and transactions ... once a final Agency ruling is obtained.” However, he never did so. The federal court eventually rendered a summary judgment against McKinney on his race discrimination claim.
McKinney then filed this suit against SAISD and its board of trustees in state court for breach of contract and to enforce the Commissioner’s reinstatement order. SAISD moved for summary judgment, pri*281marily asserting that McKinney’s suit was barred by res judicata because of the prior judgment in the federal race discrimination lawsuit. The trial court granted SAISD’s motion. The court of appeals held that because an independent school district is an arm of the state, the Eleventh Amendment prevented McKinney from bringing his state claims against SAISD in federal court and thus, res judicata did not bar his current state suit. 897 S.W.2d at 884. We disagree.
I
Because the first lawsuit at issue in this case was decided in federal court, federal law controls the determination of whether res judicata bars the present state court proceeding. Eagle Properties, Ltd. v. Scharbauer, 807 S.W.2d 714, 718 (Tex.1990); Jeanes v. Henderson, 688 S.W.2d 100, 103 (Tex.1985). Under federal law, the doctrine of res judicata will apply if (1) the parties in both suits are identical; (2) the prior judgment was rendered by a court of competent jurisdiction; (3) there is a final judgment on the merits; and (4) the same cause of action is involved in both cases. Eagle Properties, 807 S.W.2d at 718. Additionally, even if the above four requirements are established, res judicata will not apply if the federal court (1) lacked jurisdiction over the omitted state law claims, or (2) possessed jurisdiction over the omitted state law claims but would clearly have declined to exercise that jurisdiction as a matter of discretion. Id. at 718; Jeanes, 688 S.W.2d at 104.
As framed by the parties, the dispositive question is whether the federal court lacked jurisdiction because of the Eleventh Amendment. There is no question that the federal court had supplemental jurisdiction under 28 U.S.C. § 1367.1 And McKinney has not argued that had the federal court possessed jurisdiction it would clearly have declined to exercise supplemental jurisdiction over his omitted state law claims as a matter of discretion. Moreover, at oral argument, McKinney confirmed that his only argument against res judicata is that the Eleventh Amendment prevented the federal court from hearing his state law claims. Accordingly, we do not have before us the question of whether the federal district court “would clearly have declined” to exercise its supplemental jurisdiction over McKinney’s state law claims as a matter of discretion. 28 U.S.C. § 1367(c); see also Eagle Properties, 807 S.W.2d at 718; Jeanes, 688 S.W.2d at 104. Instead, we must decide whether the San Antonio Independent School District is in effect the “State” so that the federal court would have lacked jurisdiction to consider McKinney’s state law claims.
II
The Eleventh Amendment limits the federal courts’ judicial power specified in Article III, Section 2 of the United States Constitution. It provides:
The Judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by Citizens of another State, or by Citizens or Subjects of any Foreign State.
U.S. CONST, amend. XI. The Amendment by its terms does not bar suits against a state by its own citizens. However, the United States Supreme Court has consistently held that an unconsenting state is immune from suits brought in federal courts by her own citizens as well as by citizens of another state. Edelman v. Jordan, 415 U.S. 651, 662-63, 94 S.Ct. 1347, 1355-56, 39 L.Ed.2d 662 (1974) (citations omitted). Accordingly, if against the State of Texas or an arm of the state, McKinney’s claims are within the scope of the Eleventh Amendment.
By its terms, the protection afforded by the Eleventh Amendment is only available to “one of the United States.” Lake Country Estates, Inc. v. Tahoe Regional Planning Agency, 440 U.S. 391, 400, 99 S.Ct. 1171, 1177, 59 L.Ed.2d 401 (1979). As such, whether a particular governmental entity enjoys the federal constitutional protection af*282forded to the states under the Eleventh Amendment is a question of federal law. See Cowles v. Mercer, 7 Wall. 118, 19 L.Ed. 86 (1868) (state law cannot defeat jurisdiction given by the Constitution). Under federal law, some state agencies exercising state power are permitted to invoke the Amendment to protect the state treasury from liability that would have had essentially the same practical consequences as a judgment against the state itself. Lake Country, 440 U.S. at 400-01, 99 S.Ct. at 1176-77. But the United States Supreme Court has “consistently refused to construe the Amendment to afford protection to political subdivisions such as counties and municipalities, even though such entities exercise a ‘slice of state power.’ ” Id. at 401, 99 S.Ct. at 1177.
Although the ultimate question of federal jurisdiction under the Eleventh Amendment is a federal constitutional question, state law informs the determination. Mt. Healthy City Sch. Dist. Bd. of Educ. v. Doyle, 429 U.S. 274, 280, 97 S.Ct. 568, 572-73, 50 L.Ed.2d 471 (1977). Accordingly, in Mt. Healthy, the Supreme Court examined the nature of the governmental entity, there a local school district board created under Ohio law, to determine whether it was more like a county or city than it was like an arm of the State of Ohio. Id. Our task, then, is to examine the legal and functional nature of an independent school district under Texas law and determine whether it is more like a county or city, or more like an arm of the state against whom a judgment would have essentially the same effect as a judgment against the State of Texas itself.
Ill
Education of our children is an essential Texas value. Edgewood Indep. Sch. Dist. v. Meno, 917 S.W.2d 717, 725 (Tex.1995) (Edgewood IV). As such, our Texas Constitution imposes on the Legislature a duty to make suitable provision for an efficient system of public free schools. Article VII, Section 1 states:
A general diffusion of knowledge being essential to the preservation of the liberties and rights of the people, it shall be the duty of the Legislature of the State to establish and make suitable provision for the support and maintenance of an efficient system of public free schools.
Tex. Const. art. VII, § 1. The Texas Legislature has created a three tiered system for implementing its educational obligation. At the state level, we have the Texas Education Agency, headed by the Commissioner of Education, and the State Board of Education. Tex.Educ.Code §§ 7.001-.112. Regionally, the Legislature created Regional Education Service Centers. Id. §§ 8.001-.124. At the local level are independent school districts, which have been the “basis of the public school system of Texas from the days of the Republic.” Love v. City of Dallas, 120 Tex. 351, 40 S.W.2d 20, 24 (1931); see also Tex. Educ.Code §§ 11.001-.356.
The Legislature has given the Texas Education Agency and the State Board of Education only limited authority, specifically reserving for the school districts and their trustees and charter schools any educational function not delegated to the TEA or the Board. Tex.Eduo.Code §§ 7.003, 11.151(b). As a result, independent school districts have the “primary responsibility for implementing the [Sjtate’s system of public education and ensuring student performance in accordance with the code.” Id. § 11.002.
Under Texas law, independent school districts enjoy a large amount of political autonomy from the State, the TEA, and the Board. Each district is governed by a board of trustees elected by voters within a trustee district. Tex.Educ.Code §§ 11.051-063. District trustees are granted “the exclusive power and duty to govern and oversee the management of the public schools of the district.” Id. § 11.151(b). Trustees may adopt any rules or bylaws necessary to carry out their statutory powers and duties. Id. § 11.151(d). An independent school district has the power to levy and collect taxes and issue bonds. Id. §§ 11.152, 45.001-232. Independent school districts have the right, through their boards of trustees, to sue and be sued “in the name of the district.” Id. § 11.151(a). And they may acquire, hold, and sell real and personal property. Id. §§ 11.151-156. Importantly, neither the TEA nor the Board may substitute its judg*283ment for the lawful exercise by district trustees of their powers and duties. Id. § 11.151(b).
In addition, the Legislature has defined school districts as political subdivisions of the State, like cities and counties, for purposes of sovereign immunity. A “governmental unit” means:
(A) this state and all the several agencies of government that collectively constitute the government of this state, including other agencies bearing different designations, and all departments, bureaus, boards, commissions, offices, agencies, councils, and courts;
(B) a political subdivision of this state, including any city, county, school district, junior college district....
Tex.Civ.PRAC. & Rem.Code § 101.001(2)(A)-(B). The fact that a school district enjoys sovereign immunity does not mean that it is in effect the State for purposes of the Eleventh Amendment. Cities and counties enjoy sovereign immunity, City of Galveston v. Posnainsky, 62 Tex. 118, 127 (1884); Heigel v. Wichita County, 84 Tex. 392, 19 S.W. 562, 563 (1892), except to the extent abrogated by the Texas Tort Claims Act, and yet they are not entitled to Eleventh Amendment immunity. Lake Country, 440 U.S. at 401, 99 S.Ct. at 1177; Mt. Healthy, 429 U.S. at 280, 97 S.Ct. at 572.
On several occasions we have identified school districts as political entities distinct from the State. In Port Arthur Indep. Sch. Dist. v. City of Groves, 376 S.W.2d 330, 333 (Tex.1964), we held that municipal building ordinances applied to independent school districts. The issue in that case was two-fold: (1) whether the school district would be considered as the State such that a city’s police powers would not apply to the school district, and (2) if not, whether the Legislature had by statute occupied the particular field covered by the ordinance so that the city’s police powers would not apply to the school district as a political subdivision. Id. at 332-33. The Court specifically rejected case law from another jurisdiction defining the school district as the State such that a city’s ordinances would not extend to the district. Id. (citing Hall v. City of Taft, 47 Cal.2d 177, 302 P.2d 574 (1956)). We said:
Although our independent school districts are creatures of the state and receive substantial funds for their operation from the state, they are independent political entities and we will not classify their property as state property.
Id. The Court went on to note that the Legislature had vested local school boards with broad powers, but had made no provision for regulating the construction or safety of school buildings. Id. As a political subdivision of the State, we held that the city’s police powers applied to independent school districts.
Earlier, in Love, 120 Tex. 351, 40 S.W.2d 20, 25-27 (1931), we directly analogized school districts to cities, towns, and municipal corporations. School districts, we said, “are local public corporations of the same general character as municipal corporations.” Id. 40 S.W.2d at 26. They are quasi-municipal corporations. Id. As such, we held that the Legislature was without power to compel a school district to provide additional facilities or teachers for the education of students from another district. Id. 40 S.W.2d at 30; see also University Interscholastic League v. Midwestern Univ., 152 Tex. 124, 255 S.W.2d 177, 183 (1953) (independent school district is a quasi-municipal corporation that may contract to profit from football games played on its premises, subject to University Interscholastic League rules voluntarily assumed upon joining the League); State v. School Trustees of Shelby County, 150 Tex. 238, 239 S.W.2d 777, 782 (1951) (rural high school district, like common school district and independent school district, is a quasi-municipal corporation).
That Texas law defines independent school districts more like counties and cities than like an arm of the state does not end our inquiry. Eleventh Amendment immunity may extend to some state entities if a judgment against the entity would in effect be a judgment against the State. Edelman, 415 U.S. at 663, 94 S.Ct. at 1355-56; Ford Motor Co. v. Department of Treasury, 323 U.S. 459, 463, 65 S.Ct. 347, 350, 89 L.Ed. 389 (1945). While some independent school dis*284tricts receive substantial state funding, that fact alone is not determinative of whether the Eleventh Amendment’s “core concern” is implicated. See Hess v. Port Authority Trans-Hudson Corp., 513 U.S. 30, 47-51, 115 S.Ct. 394, 404-06, 130 L.Ed.2d 245 (1994) (describing the impetus for the Eleventh Amendment as the prevention of federal court judgments that must be paid out of a state’s treasury and denominating this concern as the Amendment’s “core, concern”). Even a governmental entity that receives a “significant amount of money” from the State may not be an arm of the state. Mt. Healthy, 429 U.S. at 280, 97 S.Ct. at 573. For Eleventh Amendment purposes, it is not the entity’s mere receipt of state funds that is important, but whether a money judgment against the entity must be paid with state funds. Hess, 513 U.S. at 48-50, 115 S.Ct. at 404-05.
The Legislature has designed an elaborate funding system for Texas independent school districts. Tex.Educ.Codb Ann. §§ 41.001-45.232; see Edgewood IV, 917 S.W.2d at 727-29. Generally speaking, however, Texas’ public education system is financed by ad valorem taxes generated by local school districts and supplemented with state funds. See Tex.Educ.Code Ann. §§ 42.101-.105, .251-.253, .302-.303; Edgewood IV, 917 S.W.2d at 727-29, 735; Carrollton-Farmers Branch Indep. Sch. Dist. v. Edgewood Indep. Sch. Dist., 826 S.W.2d 489, 494 (Tex.1992)(“[L]ocal ad valorem taxes now are expected to provide most of the basic needs of education.”). The most that can be said is that a judgment against a school district may be paid with funds initially appropriated to the school district by the State. However, the Eleventh Amendment is not concerned with tracing the source of funds used to satisfy a judgment. Rather, the Eleventh Amendment precludes actions against a state agency that must be paid from the state’s treasury. A judgment against a school district must be paid from the funds of the school district, whether generated locally or appropriated by the State,' not from the state treasury.
* * * ‡
We hold that an independent school district is more like a city or county than it is like an arm of the State of Texas and is amenable to suit in federal court under the Eleventh Amendment to the United States Constitution. The members of independent school district’s board of trustees sued in their official capacities, likewise, are not protected by the Eleventh Amendment. Kentucky v. Graham, 473 U.S. 159, 167, 105 S.Ct. 3099, 3106, 87 L.Ed.2d 114 (1985). Because the federal court had jurisdiction to consider McKinney’s omitted state law claims against the school district and its board of trustees, res judicata precludes subsequent litigation of those claims in state court. We reverse the judgment of the court of appeals and render judgment that McKinney take nothing.
PHILLIPS, C.J., and HECHT, OWEN, BAKER and ABBOTT, JJ., join. SPECTOR, J., filed a concurring opinion, joined by CORNYN, J. GONZALEZ, J., filed a dissenting opinion.. In any civil action in which the federal district courts have original jurisdiction, the district courts have supplemental jurisdiction over “all other claims that are so related to claims in the action within such original jurisdiction that they form a part of the same case or controversy under Article III of the United States Constitution." 28 U.S.C. § 1367(a).