Moore v. Ogilvie
The plaintiffs in the case desired to be presidential electors from Illinois in the 1968 election. However, the state's Electoral Board denied them certification for the ballot because of defects in their nominating petitions. An Illinois statute required presidential candidates to have 25,000 signatures including 200 signatures from each of at least fifty of the state's 102 counties. The plaintiff's petitions contained over 25,000 signatures, but not 200 voters from each of 50 counties.
At the district court level, the plaintiffs lost. They appealed and eventually won. The highest court reasoned that "The Illinois statute, which is an integral part of the election process, applies a rigid, arbitrary formula to sparsely settled counties and populous counties alike, and thus discriminates against the residents of the populous counties in the exercise of their political rights in violation of the Equal Protection Clause of the Fourteenth Amendment."
At the time, as evidence showed, of the state's registered voters, 93.4% lived in the 49 most populous counties, and only 6.6% in the remaining 53 counties.
Citation in Bush v. Gore
Moore v. Ogilvie was cited by the Supreme Court in its 2000 ruling in the famous case of Bush v. Gore. That ruling says, "An early case in our one person, one vote jurisprudence arose when a State accorded arbitrary and disparate treatment to voters in its different counties. Gray v. Sanders, 372 U.S. 368 (1963). The Court found a constitutional violation. We relied on these principles in the context of the Presidential selection process in Moore v. Ogilvie, 394 U.S. 814 (1969), where we invalidated a county-based procedure that diluted the influence of citizens in larger counties in the nominating process. There we observed that “[t]he idea that one group can be granted greater voting strength than another is hostile to the one man, one vote basis of our representative government."