What United States Supreme Court decision focused on how states count popular votes for president and vice president?

The decision in Bush v. Gore (2000) is significant because it addressed the issue of how states conduct the counting of popular votes during the presidential election. The case arose from the contested results of the 2000 Florida presidential election, where the accuracy and fairness of the vote-counting process were in question. The Supreme Court ruled that the Florida Supreme Court's method of recounting the votes violated the Equal Protection Clause of the Fourteenth Amendment, as the varying standards of counting in different counties could lead to unequal treatment of voters.

This ruling ultimately decided the outcome of the election, as it prevented the continuation of the recount in Florida, effectively awarding the presidency to George W. Bush. The implications of this decision extended to the principles of electoral integrity, equal protection under the law, and how states administer their electoral processes. It is a pivotal case when discussing the methods of counting and certifying votes in presidential elections.

In contrast, the other cases listed do not directly relate to the counting of votes for the presidency. U.S. v. Nixon dealt primarily with presidential privilege, Baker v. Carr focused on legislative redistricting, and Citizens United v. FEC revolved around campaign finance and free speech rather than the counting mechanisms of popular