The case of Mitchell et al. v. Donovan, Secretary of State of Minnesota, et al., revolved around the issue of whether a state could constitutionally require that voters be residents for at least 30 days before an election in order to vote. The plaintiffs were students who had moved to Minnesota for school and argued that this requirement violated their rights under the Equal Protection Clause of the Fourteenth Amendment because it treated them differently from other citizens based on their student status. However, the Supreme Court ruled against them stating that states have a legitimate interest in preventing voter fraud and ensuring orderly elections which justifies residency requirements like those in question here.

In the dissenting opinion for Mitchell et al. v. Donovan, Justice Harlan argued that the Minnesota statute in question, which required a one-year residency in the state and 90 days in an election district to vote, was not unconstitutional as it did not violate equal protection rights under the Fourteenth Amendment. He contended that states have a legitimate interest in ensuring informed voting by requiring some period of residence before granting suffrage rights to new residents. Furthermore, he believed this requirement also helps maintain fair and orderly elections by providing officials with sufficient time to verify voter eligibility and prevent fraud. Therefore, according to him, these requirements were reasonable measures designed to promote compelling state interests rather than arbitrary restrictions on voting rights.