Which principle requires legislative districts to have roughly equal populations?

• A. Equal protection of voting power
• B. One person, one vote (Reynolds v. Sims)
• C. Horizontal fairness standard
• D. Administrative efficiency standard

Answer: (B)

The central idea is that each vote must carry roughly the same weight in drawing legislative districts. This is the one person, one vote principle, established for state legislatures by Reynolds v. Sims, which holds that districts must be approximately equal in population to satisfy equal protection. When district populations differ too much, votes in smaller districts have more influence than those in larger ones, undermining equal representation. Minor, practical deviations are allowed, but large disparities are not. The other labels don’t capture this binding requirement as precisely: horizontal fairness and administrative efficiency address different concerns, while equal protection of voting power is the constitutional basis, with the established shorthand and the Reynolds v. Sims framework centering on one person, one vote.