concurring in part and dissenting in part.
I join the Court’s judgment to the extent that it remands the case to the Ninth Circuit. I agree that a remand is in order because the Court of Appeals did not attend to this Court’s reading of 28 U. S. C. § 1738 in a controlling decision, Kremer v. Chemical Constr. Corp., 456 U. S. 461 (1982). But I would not endeavor, as the Court does, to speak the first word on the content of Delaware preclusion law. Instead, I would follow our standard practice of remitting that issue for decision, in the first instance, by the lower federal courts. See, e. g., Marrese v. American Academy of Orthopaedic Surgeons, 470 U. S. 373, 387 (1985).
I write separately to emphasize a point key to the application of § 1738: A state-court judgment generally is not entitled to full faith and credit unless it satisfies the requirements of the Fourteenth Amendment’s Due Process Clause. See Kremer, 456 U. S., at 482-483. In the class-action setting, adequate representation is among the due process ingredients that must be supplied if the judgment is to bind absent class members. See Phillips Petroleum Co. v. Shutts, 472 U. S. 797, 808, 812 (1985); Prezant v. De Angelis, 636 A. 2d 915, 923-924 (Del. 1994).
Suitors in this action (called the “Epstein plaintiffs” in this opinion), respondents here, argued before the Ninth Circuit, and again before this Court, that they cannot be bound by the Delaware settlement because they were not adequately represented by the Delaware class representatives. They contend that the Delaware representatives’ willingness to release federal securities claims within the exclusive jurisdiction of the federal courts for a meager return to the class members, but a solid fee to the Delaware class attorneys, disserved the interests of the class, particularly, the absentees. The inadequacy of representation was apparent, the Epstein plaintiffs maintained, for at the time of the settle*389ment, the federal claims were sub judice in the proper forum for those claims — the federal judiciary. Although the Ninth Circuit decided the case without reaching the due process check on the full faith and credit obligation, that inquiry remains open for consideration on remand. See ante, at 379, n. 5 (due process “w[as] not the basis for the decision below,” so the Court “need not address [it]”).
I
Matsushita’s acquisition of MCA prompted litigation in state and federal courts. A brief account of that litigation will facilitate comprehension of the Epstein plaintiffs’ position. On September 26, 1990, in response to reports in the financial press that Matsushita was negotiating to buy MCA, a suit was filed in the Court of Chancery of Delaware, a purported class action on behalf of the stockholders of MCA. Naming MCA and its directors (but not Matsushita) as defendants, the complaint invoked state law only. It alleged that MCA’s directors had failed to carry out a market check to maximize shareholder value upon a change in corporate control, a check required by Revlon, Inc. v. MacAndrews & Forbes Holdings, Inc., 506 A. 2d 173, 182 (Del. 1986). For this alleged breach of fiduciary duty, the complaint sought, inter alia, an injunction against Matsushita’s proposed acquisition of MCA.
Matsushita announced its tender offer on November 26, 1990. It offered holders of MCA common stock $71 per share, if they tendered their shares before December 29, 1990. The owners of 91% of MCA’s common stock tendered their shares and, on January 3, 1991, for a price of $6.1 billion, Matsushita acquired MCA.
On December 3,1990, a few days after the required Securities and Exchange Commission (SEC) filings disclosed the terms of the tender offer, several MCA shareholders filed suit in the United States District Court for the Central Dis*390trict of California.1 Based solely on federal law, their complaints alleged that Matsushita, first named defendant, violated SEC Rules 14d — 10, 17 CFR §240.14d-10 (1994), and 10b-13, id., §240.10b-13, by offering preferential treatment in the tender offer to MCA principals Lew Wasserman and Sidney Sheinberg. As stated in the complaint, the public tender offer included a special tax-driven stock swap arrangement for Wasserman, then MCA’s chairman and chief executive officer, and a $21 million bonus for Sheinberg, then MCA’-s chief operating officer and owner of 1,170,000 shares of MCA common stock. These arrangements allegedly violated, inter alia, the SEC’s “all-holder best-price” rule (Rule 14d-10), which requires bidders to treat all shareholders on equal terms. The claims of federal securities law violations fell within the exclusive jurisdiction of the federal court. See 15 U. S. C. § 78aa. The Epstein plaintiffs also sought class certification to represent all MCA shareholders at the time of the tender offer.
Two days later, counsel in the Delaware action advised MCA’s counsel that the Delaware plaintiffs intended to amend their complaint to include additional claims against MCA and its directors and to add Matsushita as a defendant. The additional claims alleged that MCA wasted corporate assets by increasing the corporation’s exposure to liability for violation of Rules 10b-13 and 14d-10, that MCA failed to *391make full disclosure of the benefits MCA insiders would receive from the takeover, and that directors Wasserman and Sheinberg breached their fiduciary duties by negotiating preferential deals with Matsushita. Matsushita, the amended complaint alleged, had conspired with and aided and abetted MCA directors in violation of Delaware law.
Within days, the Delaware parties agreed to a settlement and, on December 17, 1990, submitted their proposal to the Delaware Vice Chancellor. The agreement provided for a modification of a “poison pill” in the corporate charter of an MCA subsidiary,2 and for a fees payment of $1 million to the class counsel. The settlement agreement required the release of all claims, state and federal, arising out of the tender offer.
The Vice Chancellor rejected the settlement agreement on April 22, 1991, for two reasons: the absence of any monetary benefit to the class members; and the potential value of the federal claims that the agreement proposed to release. The “generous payment” of $1 million in counsel fees, the Vice Chancellor observed, “conferred] no benefit on the members of the Class.” In re MCA, Inc. Shareholders Litigation, 598 A. 2d 687, 695 (Del. Ch. 1991). And the value of the revised poison pill to the class, the Vice Chancellor said, was “illu-sionary[,] . . . apparently . . . proposed merely to justify a settlement which offers no real monetary benefit to the Class.” Id., at 696. The Vice Chancellor described the state-law claims as “at best, extremely weak and, therefore, [of] little or no value.” Id., at 694. “[T]he only claims which have any substantial merit,” he said, “are the claims . . . in the California federal suit that were not asserted in this Delaware action.” Id., at 696. After the rejection of *392the settlement, the Delaware lawsuit lay dormant for more than a year.
The federal litigation proceeded. In various rulings, the District Court denied the federal plaintiffs’ motion for partial summary judgment, denied the Epstein plaintiffs’ motion for class certification, and granted Matsushita’s motion for summary judgment dismissing the claims. On April 15, 1992, the District Court entered its final judgment, which the Epstein plaintiffs appealed to the Ninth Circuit.
On October 22, 1992, after the federal plaintiffs had filed their notice of appeal, the Delaware parties reached a second settlement agreement. Matsushita agreed to create a $2 million settlement fund that would afford shareholders 2 to 3 cents per share before payment of fees and costs. The Delaware class counsel requested $691,000 in fees. In return for this relief, the Delaware plaintiffs agreed to release “all claims, rights and causes of action (state or federal, including but not limited to claims arising under the federal securities laws, and any rules or regulations promulgated thereunder, or otherwise)... in connection with or that arise now or hereafter out of the [tender offer] . . . including without limitation the claims asserted in the California Federal Actions . . . .” App. 187-188. Unlike the first settlement proposal, the second agreement included an opt-out provision.
This time the Vice Chancellor approved the settlement. He stated: “[I]t is in the best interests of the class to settle this litigation and the terms of the settlement are fair and reasonable — although the value of the benefit to the class is meager.” In re MCA, Inc. Shareholders Litigation, C. A. No. 11740, 1993 WL 43024, *1 (Del. Ch., Feb. 16, 1993). He found the class members’ recovery of 2 to 3 cents per share “adequate (if only barely so) to support the proposed settlement.” Id., at *4. The federal claims, he reasoned, having been dismissed by the District Court, “now have minimal economic value.” Ibid. And he gave weight to the pres*393ence in the second settlement agreement of an opt-out provision. Ibid.
Addressing the objectors’ contention that the proposed settlement was “collusive,” the Vice Chancellor recalled that “the settling parties ha[d] previously proposed a patently inadequate settlement,” and he agreed that “suspicions abound.” Id., at *5. Nevertheless, he noted, the “[objectors have offered no evidence of any collusion,” so he declined to reject the settlement on that ground. Ibid. Reducing the counsel fees from the requested $691,000 to $250,000, the Vice Chancellor offered this observation: “[T]he defendants’ willingness to create the settlement fund seems likely to have been motivated as much by their concern as to their potential liability under the federal claims as by their concern for liability under the state law claims which this Court characterized as ‘extremely weak.’” Id., at *6. In a brief order, the Delaware Supreme Court affirmed “on the basis of and for the reasons assigned by the Court of Chancery . .. .” In re MCA, Inc. Shareholders Litigation, C. A. No. 126, 1993, 1993 WL 385041, *1 (Sept. 21, 1993), judgt. order reported at 633 A. 2d 370.
Before the Ninth Circuit, Matsushita argued that the Delaware class-action settlement barred litigation of the federal claims raised in the Epstein action. The Ninth Circuit disagreed. Relying on Federal Circuit Court decisions,3 the Court of Appeals held that state courts lack plenary power to approve settlements that effectively extinguish exclusively federal claims. Only if federal and state claims rest on the “identical factual predicate,” the Ninth Circuit concluded, could a state-court settlement subsume an exclusively federal claim. It was not enough, in the Ninth Circuit’s view, that the discrete federal and state claims stem from the *394“same transaction,” the test Matsushita urged. 50 F. 3d, at 661-665. The federal securities claims did not turn on the same operative facts as the state claims pleaded in Delaware, the Ninth Circuit found; accordingly, the federal claims could not have been extinguished by the issue-preclusive effect of an adjudication of the state claims. This analysis led the Ninth Circuit to declare that the Delaware decree “exceeded] the jurisdiction of the state court and, therefore, is not entitled to full faith and credit.” Id., at 666.
On the merits, the Ninth Circuit held, first, that a private right of action could be maintained to redress Rule 14d-10 violations. Id., at 652. The court next held that Matsu-shita violated Rule 14d-10 by paying Wasserman consideration not offered to other shareholders, id., at 657; reversing the District Court’s disposition of this matter, the Ninth Circuit held that plaintiffs were entitled to summary judgment on liability and remanded for a determination of damages, ibid. Regarding plaintiffs’ claim that the $21 million payment to Sheinberg violated Rule 14d-10, the Ninth Circuit vacated the summary judgment for Matsushita and remanded for a determination whether the payment was in fact made to encourage Sheinberg to tender his shares. Id., at 659.
II
A
Section 1738’s full faith and credit instruction, as the Court indicates, requires the forum asked to recognize a judgment first to determine the preclusive effect the judgment would have in the rendering court. See Kremer, 456 U. S., at 466; Marrese, 470 U. S., at 381. Because the Ninth Circuit did not evaluate the preclusive effect of the Delaware judgment through the lens of that State’s preclusion law, I would remand for that determination. See id., at 386-387; Migra v. Warren City School Dist. Bd. of Ed., 465 U. S. 75, 87 (1984) (“Prudence . . . dictates that it is the District Court, in the *395first instance, not this Court, that should interpret Ohio preclusion law and apply it.”).4
B
Every State’s law on the preclusiveness of judgments is pervasively affected by the supreme law of the land. To be valid in the rendition forum, and entitled to recognition nationally, a state court’s judgment must measure up to the requirements of the Fourteenth Amendment’s Due Process Clause. Kremer, 456 U. S., at 482-483. “A State may not grant preclusive effect in its own courts to a constitutionally infirm judgment, and other state and federal courts are not required to accord full faith and credit to such a judgment.” Id., at 482 (footnote omitted).
In Phillips Petroleum Co. v. Shutts, this Court listed minimal procedural due process requirements a class-action money judgment must meet if it is to bind absentees; those requirements include notice, an opportunity to be heard, a right to opt out, and adequate representation. 472 U. S., at 812. “[T]he Due Process Clause of course requires that the named plaintiff at all times adequately represent the interests of the absent class members.” Ibid, (citing Hansberry v. Lee, 311 U. S. 32, 42-43, 45 (1940)). As the Shutts Court’s phrase “at all times” indicates, the class representative’s duty to represent absent class members adequately is a continuing one. 472 U. S., at 812; see also Gonzales v. Cassidy, 474 F. 2d 67, 75 (CA5 1973) (representative’s failure to pursue an appeal rendered initially adequate class representation inadequate, so that judgment did not bind the class).
Although emphasizing the constitutional significance of the adequate representation requirement, this Court has recog*396nized the first line responsibility of the States themselves for assuring that the constitutional essentials are met. See Hansberry, 311 U. S., at 42.5 Final judgments, however, remain vulnerable to collateral attack for failure to satisfy the adequate representation requirement. See id., at 40,42; see also Restatement (Second) of Judgments §§ 42(d) and (e), Comments e and f pp. 406, 410-412 (1982) (noting, inter alia, that judgment is not binding on purportedly represented person where, to the knowledge of the opposing party, the representative seeks to advance his own interest at the expense of the represented person); see also id., §41, Comment a, p. 394 (if § 42 circumstances exist, “the represented person may avoid being bound either by appearing in the action before rendition of the judgment or by attacking the judgment by subsequent proceedings”). (Emphasis added.) A court conducting an action cannot predetermine the res judicata effect of the judgment; that effect can be tested only in a subsequent action. See 7B C. Wright, A. Miller, & M. Kane, Federal Practice and Procedure § 1789, p. 245 (2d ed. 1986).
In Delaware, the constitutional due process requirement of adequate representation is embodied in Delaware Court of Chancery’s Rule 23, a class-action rule modeled on its federal counterpart. Prezant, 636 A. 2d, at 923, 920. Delaware requires, as a prerequisite to class certification, that the named *397plaintiffs “fairly and adequately protect the interests of the class.” Del. Ch. Rule 23(a)(4). In Prezant, the Delaware Supreme Court considered whether adequate class representation was “a sine qua non for approval of a class action settlement,” and concluded that it was. 636 A. 2d, at 920, 926. The state high court overturned a judgment and remanded a settlement because the Court of Chancery had failed to make an explicit finding of adequate representation. Id., at 926.
The Delaware Supreme Court underscored that due process demands more than notice and an opportunity to opt out; adequate representation, too, that court emphasized, is an essential ingredient. Id., at 924 (citing Phillips Petroleum Co. v. Shutts, 472 U. S., at 812). Notice, the Delaware Supreme Court reasoned, cannot substitute for the thorough examination and informed negotiation an adequate representative would pursue. Prezant, 636 A. 2d, at 924. The court also recognized that opt-out rights “are infrequently utilized and usually economically impracticable.” Ibid.
The Vice Chancellor’s evaluation of the merits of the settlement could not bridge the gap, the Delaware Supreme Court said, because an inadequate representative “taintfs]” the entire settlement process. Id., at 925.6 “[A]n adequate representative,” the Delaware Supreme Court explained, “vigorously prosecuting an action without conflict and bargaining at arms-length, may present different facts and a *398different settlement proposal to the court than would an inadequate representative.” Ibid. Consequently, the Delaware Supreme Court held, “in every class action settlement, the Court of Chancery is required to make an explicit determination on the record of the propriety of the class action according to the requisites of Rule 23(a) and (b).” Ibid.
In the instant case, the Epstein plaintiffs challenge the preclusive effect of the Delaware settlement, arguing that the Vice Chancellor never in fact made the constitutionally required determination of adequate representation. See id., at 923.7 They contend that the state court left unresolved key questions: notably, did the class representatives share substantial common interests with the absent class members, and did counsel in Delaware vigorously press the interests of the class in negotiating the settlement.8 In particular, the Epstein plaintiffs question whether the Delaware class representatives — who filed the state lawsuit on September 26, 1990, two months before the November 26 tender offer announcement — actually tendered shares in December, thereby enabling them to litigate a Rule 14d-10 claim in federal court. They also suggest that the Delaware representatives undervalued the federal claims — claims they could only settle, but never litigate, in a Delaware court. Finally, *399the Epstein plaintiffs contend that the Vice Chancellor improperly shifted the burden of proof;9 he rejected the Delaware objectors’ charges of “collusion” for want of evidence while acknowledging that “suspicions [of collusion] abound.” In re MCA, Inc. Shareholders Litigation, 1993 WL 43024, at *5.10
Mindful that this is a court of final review and not first view, I do not address the merits of the Epstein plaintiffs’ contentions, or Matsushita’s counterargument that the issue of adequate representation was resolved by fall and fair litigation in the Delaware Court of Chancery.11 These arguments remain open for airing on remand. I stress, however, the centrality of the procedural due process protection of adequate representation in class-action lawsuits, emphatically including those resolved by settlement. See generally J. Coffee, Suspect Settlements in Securities Litigation, N. Y. L. J., March 28, 1991, p. 5, col. 1.
Two sets of plaintiffs filed complaints in the Central District of California: the Epstein plaintiffs (including Lawrence Epstein, John Linder, Jane Rockford, Maurice Karlin, Ruth Karlin, Beth Karlin, and Bert Karlin) sued both individually and on behalf of all MCA shareholders at the time of the tender offer; Walter Minton brought suit in his individual capacity. All had tendered their shares for the $71 tender price. The District Court consolidated the two cases. Minton and, it appears, Rockford opted out of the Delaware class-action settlement. Matsushita does not contest the qualification of Minton and Rockford, as individuals, to pursue federal claims unimpeded by the settlement in Delaware. See Brief for Petitioners ii. Matsushita does contest any class-action initiative in federal court.
The subsidiary in question was spun off from MCA during the merger because it owned a television station that federal law prohibited Matsushita from acquiring. The $71 tender offer price included $5 worth of stock in this new corporation.
Closest in point, the court said, were Grimes v. Vitalink Communications Corf., 17 F. 3d 1553 (CA3 1994), and Nottingham Partners v. Trans-Lux Corf., 925 F. 2d 29 (CA1 1991). See Efstein v. MCA, Inc., 50 F. 3d 644, 662 (CA9 1995).
In its endeavor to forecast Delaware preclusion law, the Court appears to have blended the “identical factual predicate” test applied by the Delaware Supreme Court in Nottingham Partners v. Dana, 564 A. 2d 1089, 1106-1107 (1989), with the broader “same transaction” test advanced by Matsushita. See ante, at 376-378.
Many States, including Delaware, have class-action rules corresponding to Federal Rule of Civil Procedure 23, a rule ranking adequacy of representation as a prerequisite to maintaining a class action. See 3 H. Newberg & A. Conte, Newberg on Class Actions, App. 13-1 (3d ed. 1992) (listing 39 States and the District of Columbia with rules comparable to the amended Federal Rule of Civil Procedure 23); Fed. Rule Civ. Proc. 23(a)(4) (representatives may sue on behalf of the class only if “the representative parties will fairly and adequately protect the interests of the class”); see also General Telephone Co. of Southwest v. Falcon, 457 U. S. 147, 157-158, n. 13 (1982) (Federal Rule of Civil Procedure 23(a)(4)’s adequate representation requirement “raises concerns about the competency of class counsel and conflicts of interest,” in addition to the question whether the representative shares the interests of the class members).
In both Prezant and the instant ease, a temporary settlement class device was used, telescoping the inquiry of adequate representation into the examination of the fairness of the settlement. According to the Delaware Supreme Court, however, this near simultaneity does not relieve the representative of her duty to demonstrate, nor the court of its duty to determine, the adequacy of representation. Prezant, 636 A. 2d, at 923. In a comprehensive opinion, the Third Circuit reached the same conclusion after examining the temporary class settlement device in the context of Federal Rule of Civil Procedure 23. See In re General Motors Corp. Pick-up Truck Fuel Tank Products Liability Litigation, 55 F. 3d 768, 794-800 (1995).
The Vice Chancellor did not have the benefit of the Delaware Supreme Court’s clear statement in Premnt, decided one year after this settlement was approved. In Prezant, however, the Delaware Supreme Court largely reiterated and applied what this Court had stated almost a decade earlier in Phillips Petroleum Co. v. Shutts, 472 U. S. 797, 808, 812 (1985). See also 2 R. Balotti & J. Finkelstein, Delaware Law of Corporations and Business Organization § 13.22, p. 13-131, and n. 578 (2d ed. 1996 Supp.).
The order approving the class for settlement purposes, the Epstein plaintiffs urge, contains no discussion of the adequacy of the representatives, see App. 198, and the order and final judgment approving the settlement contains only boilerplate language referring to the adequacy of representation, see id., at 204-205. The Delaware Supreme Court approved the Court of Chancery’s judgment in a one paragraph order. See In re MCA, Inc. Shareholders Litigation, 633 A. 2d 370 (1993) (judgt. order).
Delaware law appears to place the burden of proof on the class representatives. See 2 Balotti & Finkelstein, supra, at 11, n. 7, §13-17, p. 13-121 (class representative must prove satisfaction of Del. Ch. Rule 23(a) requirements, including adequacy of representation); see also 7A C. Wright, A. Miller, & M. Kane, Federal Practice and Procedure §1765, pp. 273-274, and n. 29 (2d ed. 1986); 3B J. Moore, Moore’s Federal Practice §23.02-2 (2d ed. 1995).
In this regard, it is noteworthy that Matsushita did not move to dismiss the Delaware action after the Vice Chancellor, in rejecting the first proposed settlement, surveyed the state-law claims and found them insubstantial. See In re MCA, Inc. Shareholders Litigation, 598 A. 2d 687, 694 (Del. Ch. 1991) (Vice Chancellor described “the asserted state law claims” as “at best, extremely weak” and of “little or no value”).
Counsel for Matsushita acknowledged that relief from a judgment may be sought in Delaware pursuant to that State’s counterpart to Federal Rule of Civil Procedure 60(b). See Tr. of Oral Arg. 51-52; Del. Ch. Rule 60; see also 2 Newberg & Conte, supra, at 9, n. 5, §§ 11.27, 11.63 (Federal Rule of Civil Procedure 60(b) provides an avenue to challenge the adequacy of representation in a class settlement).