In Marston et al. v. Lewis et al., the U.S Supreme Court was asked to determine whether an Arizona statute requiring voters to register 50 days before a general election violated the Equal Protection Clause of the Fourteenth Amendment. The plaintiffs argued that this law disenfranchised new residents and those who became of voting age within that period, thus violating their constitutional rights. However, in a per curiam decision (a ruling issued collectively by multiple judges), the court upheld the constitutionality of Arizona's voter registration deadline, stating it served compelling state interests such as preventing fraud and giving officials sufficient time to prepare for elections. The court found no evidence suggesting that these deadlines were designed or used unfairly against any particular group or individual.

In the dissenting opinion for Marston et al. v. Lewis et al., Justice William O. Douglas argued that Arizona's requirement of a 50-day residency prior to voting in state elections was unconstitutional, violating both the Equal Protection Clause and the Due Process Clause of the Fourteenth Amendment. He believed that this law unjustly discriminated against new residents by denying them their fundamental right to vote, which he considered as important as freedom of speech or assembly. Furthermore, he contended that there were less restrictive means available to achieve Arizona's stated goals of preventing voter fraud and ensuring an informed electorate without infracment on citizens' rights.