In the case of Hughes et al. v. Superior Court of California for Contra Costa County, 1949, the U.S Supreme Court ruled in favor of a group of African American petitioners who were challenging racially discriminatory housing practices in California. The court held that judicial enforcement by state courts of private restrictive covenants based on race was unconstitutional and violated the Equal Protection Clause under Fourteenth Amendment to United States Constitution. These covenants had been used to prevent people from certain racial or ethnic groups from buying or occupying property in predominantly white neighborhoods. This decision marked an important step towards ending legally sanctioned residential segregation in America.

In the dissenting opinion for Hughes et al. v. Superior Court of California for Contra Costa County, Justice Frankfurter argued that the majority's decision to uphold a state law requiring union shop agreements in collective bargaining was an overreach of federal power and infringed upon states' rights. He contended that Congress did not intend to occupy the entire field of labor relations when it passed the National Labor Relations Act (NLRA), but rather sought to provide minimum standards while allowing states flexibility in their own regulations. The justice believed that California's law was consistent with this intent and should be upheld as a valid exercise of its police powers, even if it went beyond what federal law required or permitted. Furthermore, he pointed out inconsistencies between this case and previous Supreme Court decisions regarding preemption under NLRA, suggesting there were double standards at play.