In University of Texas Southwestern Medical Center v. Nassar, 570 U.S. ___ (2013), the Supreme Court held that Title VII retaliation claims must be proved according to traditional principles of but-for causation, not the lessened causation stated in §2000e-2(m).   Dr. Nassar, a physician of Middle Eastern descent who was both a University faculty member and a Hospital staff physician, claimed that Dr. Levine, one of his supervisors at the University, was biased against him on account of his religion and ethnic heritage. He complained to Dr. Fitz, Levine’s supervisor. But after Dr. Nassar arranged to continue working at the Hospital without also being on the University’s faculty, he resigned his teaching post and sent a letter to Fitz and others, stating that he was leaving because of Levine’s harassment. Fitz, upset at Levine’s public humiliation and wanting public exoneration for her, objected to the Hospital’s job offer, which was then withdrawn. Dr. Nasser filed suit, alleging two discrete Title VII violations. First, he alleged that Levine’s racially and religiously motivated harassment had resulted in his constructive discharge from the University, in violation of 42 U. S. C. §2000e–2(a), which prohibits an employer from discriminating against an employee “because of such individual’s race, color, religion, sex, and national origin”. Second, he claimed that Fitz’s efforts to prevent the Hospital from hiring him were in retaliation for complaining about Levine’s harassment, in violation of §2000e–3(a), which prohibits employer retaliation “because [an employee] has opposed . . . an unlawful employment practice . . . or . . . made a [Title VII] charge.” 

The Court determined that §2000e-2(m)'s test of motivating factor does not apply to Title VII retaliation cases.  Title VII’s antiretaliation provision appears in a different section from its status-based discrimination ban. And, like §623(a)(1), the ADEA provision in another Supreme Court case, §2000e–3(a) makes it unlawful for an employer to take adverse employment action against an employee “because” of certain criteria. Given the lack of any meaningful textual difference between §2000e–3(a) and §623(a)(1), the proper conclusion is that Title VII retaliation claims require proof that the desire to retaliate was the but-for cause of the challenged employment action. The Court found that the proper interpretation and implementation of §2000e–3(a) and its causation standard are of central importance to the fair and responsible allocation of resources in the judicial and litigation systems, particularly since retaliation claims are being made with ever increasing frequency. Lessening the causation standard could also contribute to the filing of frivolous claims, siphoning resources from efforts by employers, agencies, and courts to combat workplace harassment.