Which case established the 'one person, one vote' principle for state legislative districts?

• A. Reynolds v. Sims (1964)
• B. Baker v. Carr (1962)
• C. Shaw v. Reno (1993)
• D. Wesberry v. Sanders (1964)

Answer: (A)

The main idea being tested is that each vote must carry roughly the same weight in state legislative elections. Reynolds v. Sims (1964) ruled that state legislative districts must be apportioned so that each district has about the same number of people, ensuring equal influence of votes across districts. This decision built on Baker v. Carr, which allowed federal courts to intervene in redistricting cases, and it applies the Equal Protection Clause to how states draw their legislative maps. The result is that malapportioned maps—where some districts have many more or fewer people than others—violate the principle that each citizen’s vote should count equally. It’s important to distinguish this from Wesberry v. Sanders, which applies the same “one person, one vote” standard to congressional districts, not state legislatures. Reynolds thus established the equal-population requirement for state legislative districts.