It's clear that five justices on the Supreme Court do not like the mixed-motive analysis that a different Court in 1989 devised in Price Waterhouse v. Hopkins, 490 U.S. 228. The Court's aversion to Price Waterhouse is evident in Gross v. FBL Financial Services, decided on December 18.
The issue in Gross was whether plaintiffs in age discrimination cases are entitled to a "mixed-motive" instruction if they proffer evidence that age played a motivating role in the adverse decision, i.e., termination or demotion. Under the Price Waterhouse rule, once the plaintiff satisfies his burden in showing that age played at least a motivating factor in the decision, the employer has to prove that it would have made the same decision even without taking age into account. Price Waterhouse was bolstered a few years ago in Desert Palace v. Costa, 539 U.S. 90 (2003), when the Court held that circumstantial (and not just direct) evidence is enough to trigger the Price Waterhouse instruction.
The Price Waterhouse instruction helps plaintiffs at trial, as often more than one reason explains why an employer mistreats the plaintiff. The employer may have been motivated by both illegal (race or gender) reasons and also legal (insubordination) reasons. An illegal motivating factor among many legal reasons is all it takes to win, and while the employer may insist that the plaintiff was fired because of poor job performance, if the Price Waterhouse instruction is given to the jury, the employer has the difficult task of proving that it would have fired the plaintiff even without considering the illegal factor.
The two primary employment discrimination laws are Title VII of the Civil Rights Act of 1964 (prohibiting discrimination because of race, gender, national origin, religion and color) and the Age Discrimination in Employment Act of 1967. The statutes are nearly indistinguishable, and courts routinely apply Title VII standards in evaluating ADEA cases, and vice-versa. What the Supreme Court is telling us in Gross is that the statutes should sometimes interpreted differently. In a footnote, the Court reminds us that it has never definitively held that the well-known McDonnell-Douglas burden shifting scheme applicable under Title VII also applies to ADEA claims. (Notwithstanding that observation, the Courts of Appeal have always assumed otherwise).
A Price Waterhouse instruction is not appropriate in ADEA cases, the 5-4 Supreme Court majority says, because "unlike Title VII, the ADEA's text does not provide that a plaintiff may establish discrimination by showing that age was simply a motivating factor." Rather, the ADEA requires that the plaintiff prove that he was discriminated "because of age." Writing for the majority, Justice Thomas perceives this distinction significant enough to limit the Price Waterhouse rule to Title VII cases. The Court interprets ADEA's "because of" language to mean that "age was the 'reason' that the employer decided to act."
The conservative majority on the Supreme Court does not shy away from distancing itself from precedents that it does not like. They do not care for Price Waterhouse, and they say so directly: "it is far from clear that the Court would have the same approach were it to consider the question today in the first instance." After summarizing Price Waterhouse's deficiencies and the fact that some Courts of Appeal have expressed frustration how that burden-shifting scheme applies in practice, the Court states that "even if Price Waterhouse was doctrinally sound, the problems associated with its application have eliminated any perceivable benefit to extending its framework to ADEA claims."
In dissent, Justice Stevens notes that Congress endorsed the Price Waterhouse mixed motive theory when it amended Title VII in 1991. He further argues that since Title VII and ADEA employ nearly identical language, Price Waterhouse should apply in ADEA claims also.