In the Holt et al. v. Virginia case of 1964, the U.S Supreme Court ruled that a state law requiring racial segregation in public transportation was unconstitutional and violated the Equal Protection Clause of the Fourteenth Amendment. The case involved six African American residents of Virginia who were convicted under a state law for refusing to sit in their designated seats on an interstate bus journey from South Carolina to Virginia. They challenged their convictions arguing that they had been denied equal protection under federal laws which prohibited racial discrimination in interstate commerce and travel. The court unanimously held that such state-imposed segregation is patently unconstitutional, thereby overturning their convictions.

In the dissenting opinion for Holt et al. v. Virginia, Justice Harlan argued that the majority's decision was a departure from established legal principles and precedent regarding state sovereignty in criminal law enforcement. He contended that there was no constitutional violation in this case as it involved an intrastate crime which should be under state jurisdiction, not federal oversight or intervention. Furthermore, he expressed concern about potential overreach by the federal government into areas traditionally controlled by states and warned of possible negative consequences to our system of federalism if such trends continued unchecked. In his view, only when there is clear evidence of racial discrimination or other egregious abuses should the Supreme Court intervene in matters pertaining to local law enforcement practices.