Williams v. Rhodes

Ohio (defendant) automatically placed on the presidential ballot any party that won 10 percent of the vote in the last gubernatorial election, but forced other parties, like the Ohio American Independent Party (plaintiffs), to meet demanding conditions: a petition filed nine months before the election signed by at least 15 percent of the prior gubernatorial vote, a rigorous primary, and an elaborate party structure. The combined effect gave the Republican and Democratic parties a near-monopoly on ballot access.

Whether a state law that places unequal burdens on minority political parties must be justified by a compelling state interest under the Equal Protection Clause.