Fed. R. Civ. P. 23 does not set forth a mere pleading standard. A party seeking class certification must affirmatively demonstrate his compliance with the Rule—that is, he must be prepared to prove that there are in fact sufficiently numerous parties, common questions of law or fact, etc. Sometimes it may be necessary for a court to probe behind the pleadings before coming to rest on the certification question, and certification is proper only if the trial court is satisfied, after a rigorous analysis, that the prerequisites of Rule 23(a) have been satisfied. Actual, not presumed, conformance with Rule 23(a) remains indispensable. Frequently that "rigorous analysis" will entail some overlap with the merits of the plaintiff's underlying claim. That cannot be helped. The class determination generally involves considerations that are enmeshed in the factual and legal issues comprising the plaintiff's cause of action. Nor is there anything unusual about that consequence: The necessity of touching aspects of the merits in order to resolve preliminary matters, e.g., jurisdiction and venue, is a familiar feature of litigation.
Respondent Betty Dukes and other current or former employees ("employees") of petitioner Wal-Mart Stores, Inc., filed an action against Wal-Mart in federal district court seeking injunctive and declaratory relief, punitive damages, and backpay, on behalf of themselves and a nationwide class of some 1.5 million female employees, because of Wal-Mart's alleged discrimination against women in violation of Title VII of the Civil Rights Act of 1964. They claimed that local managers exercised their discretion over pay and promotions disproportionately in favor of men, which had an unlawful disparate impact on female employees. Moreover, they claimed, Wal-Mart's refusal to cabin its managers' authority amounted to disparate treatment. The district court certified the class, finding that the employees satisfied Federal Rule of Civil Procedure 23(a), and Rule 23(b)(2)'s requirement of showing that the party opposing the class has acted or refused to act on grounds that applied generally to the class, so that final injunctive relief or corresponding declaratory relief was appropriate respecting the class as a whole. On appeal, the United States Court of Appeals for the Ninth Circuit substantially affirmed, concluding that the employees met Rule 23(a)(2)'s commonality requirement and that their backpay claims could be certified as part of a Rule 23(b)(2) class because those claims did not predominate over the requests for declaratory and injunctive relief. It also ruled that the class action could be manageably tried without depriving Wal-Mart of its right to present its statutory defenses if the district court selected a random set of claims for valuation and then extrapolated the validity and value of the untested claims from the sample set.
Did the putative class members meet Federal Rule of Civil Procedure 23(a)'s commonality requirement?
The Supreme Court of the United States held that the employees' class could not be certified because the action did not satisfy the commonality requirement of Fed. R. Civ. P. 23(a)(2). According to the Court, the employees failed to offer significant proof that Wal-Mart operated under a general policy of discrimination. An expert who testified that Wal-Mart had a strong corporate culture that made it vulnerable to gender bias did not determine how often stereotypes played a meaningful role in employment decisions. The Court found that the employees' statistical and anecdotal evidence did not show that a common mode of exercising managerial discretion pervaded the entire company. In addition, the employees' backpay claims were improperly certified under Rule 23(b)(2), which did not allow certification of monetary relief claims that were not incidental to injunctive or declaratory relief.