The ruling along the court's ideological fault line could have repercussions in workplaces across the United States.
Justice Ruth Bader Ginsburg dissented, and was joined by the court's three other liberals.
"The [Supreme] Court today strikes from the supervisory category employees who control the day-to-day schedules and assignments of others, confining the category to those formally empowered to take tangible employment actions," Ginsburg said. "The limitation the court decrees diminishes the force of [Supreme Court precedent], ignores the conditions under which members of the work force labor, and disserves the objective of Title VII [of the Civil Rights Act] to prevent discrimination from infecting the nation's workplaces."
Under Title VII, an employer's liability for workplace harassment may depend on the status of the harasser. If the harassing employee is the victim's co-worker, the employer is liable only if it was negligent in controlling working conditions.
In cases in which the harasser is a "supervisor," different rules apply. If the supervisor's harassment ends in a tangible employment action -- a significant change in employment status, such as hiring, firing, failing to
promote, reassignment with significantly different responsibilities, or a decision causing a significant change in benefits -- the employer is strictly liable.
An employer has a defense if it exercised reasonable care to prevent and correct any harassing behavior and that the alleged victim unreasonably failed to take advantage of the preventive or corrective opportunities that the employer provided.
Maetta Vance, a black woman, sued her employer, Ball State University in Indiana. She alleged a fellow employee, Saudra Davis, created a racially hostile work environment in violation of Title VII.
Vance said Davis, a white woman, was a supervisor because she was above her in employment status.
A federal judge granted summary judgment to BSU, saying it was not liable because Davis could not take tangible employment actions against Vance, and was therefore not a supervisor. A federal appeals court affirmed.
The Supreme Court's majority opinion, written by Justice Samuel Alito, ruled an employee is a "supervisor" for purposes of vicarious liability under Title VII -- liability of the employer -- only if he or she has been given power by the employer to take tangible employment actions against the victim.'
Vance erred "in relying on the meaning of 'supervisor' in general usage and in other legal contexts because the term has varying meanings both in colloquial usage and in the law," the opinion said.