The Eleventh Amendment 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.” This Amendment has been interpreted to mean that states often cannot be sued in federal court. This presents a problem when several civil rights/employment discrimination laws specifically provide that states can be sued.

The Rehnquist Court decided numerous cases dealing with this thorny constitutional problem. In Kimel v. Florida Board of Regents (2000), the Court ruled that Congress exceeded its constitutional powers under Section 5 of the Fourteenth Amendment when it eliminated states’s sovereign immunity. “Congress’s failure to uncover any significant pattern of unconstitutional discrimination here confirms that Congress had no reason to believe that broad prophylactic legislation was necessary in this field,” Justice Sandra Day O’Connor wrote for the Court. “In light of the indiscriminate scope of the Act’s substantive requirements, and the lack of evidence of widespread and unconstitutional age discrimination by the States, we hold that the ADEA [Age Discrimination in Employment Act] is not a valid exercise of Congress’s power under section 5 of the Fourteenth Amendment. The ADEA’s purported abrogation of the States’ sovereign immunity is accordingly invalid.” Similarly, in Board of Trustees of Univ. of Ala. v. Garrett, the Court ruled that Congress exceeded its authority in abrogating state immunity from suits by individuals under the Americans with Disabilities Act (ADA).

However, the Court changed course in a case involving the Family and Medical Leave Act (FMLA) of 1993. In Nevada Department of Human Resources v. Hibbs (2003), the Court held 6–3 that state workers may sue their employers for failure to comply with the 1993 FMLA. The decision departed from the Kimel and Garrett line of cases that immunized states from employees suing under a series of federal laws.

Chief Justice William Rehnquist distinguished Garrett and Kimel because those cases involved age- and disability-based distinctions, which the court reviews under a less intense standard. “Here, however, Congress directed its attention to state gender discrimination, which triggers a heightened level of scrutiny,” Rehnquist wrote.