In the case of Liberty Mutual Insurance Co. v. Wetzel et al., 1975, the United States Supreme Court dealt with issues related to sex discrimination in employment practices under Title VII of the Civil Rights Act of 1964. The plaintiff, a female employee at Liberty Mutual Insurance Company, filed a class action lawsuit alleging that her employer had engaged in systemic gender-based wage and promotion discrimination against its female employees nationwide. The District Court dismissed her complaint for failing to meet certain procedural requirements but was reversed by the Appeals court which held that she could represent all similarly situated women employed by Liberty Mutual across America since it was impractical for each woman to file individual suits given their common grievances about company-wide policies and practices. The Supreme Court affirmed this decision stating that such broad representation is permissible under Rule 23(b)(2) if plaintiffs can demonstrate that they are part of an identifiable group who have suffered from general policy or practice violations rather than isolated incidents specific only to them individually.

In the dissenting opinion for Liberty Mutual Insurance Co. v. Wetzel et al., Justice William Rehnquist argued that the majority's decision to allow a class action lawsuit against an insurance company for sex discrimination was incorrect because it misinterpreted Title VII of the Civil Rights Act of 1964. He contended that this law only applies to employers, employment agencies, and labor organizations - not insurers like Liberty Mutual who provide disability benefits as part of an employer’s compensation package but do not make hiring or firing decisions themselves. Furthermore, he disagreed with the majority's view that providing lower disability benefits to pregnant women than other temporarily disabled employees constituted unlawful sex discrimination under Title VII; instead, he believed such differential treatment reflected biological realities rather than prejudice or stereotypes about women's abilities or roles in society.