Verified snapshot · October 30, 2026
Israel Civic Atlas USA USA

Concepts made simple

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Redistricting and gerrymandering

Every ten years the lines are redrawn. Who draws them can decide a seat before a single vote is cast.

Every ten years the census counts everyone. The 435 House seats are then shared among the states by population.

All steps in text
  1. Every ten years the census counts everyone. The 435 House seats are then shared among the states by population.
  2. Each state redraws its district map. In most states the legislature draws it; some use an independent commission.
  3. Districts must have nearly equal population, and the Voting Rights Act bars maps that dilute the votes of racial minorities.
  4. Drawing lines to favor a party or an incumbent: packing the other side’s voters into a few districts, or cracking them thinly across many.
  5. In 2019 the Supreme Court held that federal courts will not police partisan gerrymanders. State courts and state constitutions still can, and several states redrew maps again in 2025 and 2026.

✗It seems that District lines are fixed and neutral.

✓Actually They are drawn by people, usually politicians, and can be redrawn mid-decade. The lines often matter more than the campaign.

Why it matters

In a district drawn safe for one party, the general election is decided in advance and the primary becomes the real contest.

See it in the data

Source: Census: Strength in Numbers (October 30, 2026) · AP: district boundaries and political advantage (October 30, 2026) · Library of Congress: Wesberry v. Sanders, official Reports (October 30, 2026) · Supreme Court: Rucho v. Common Cause (October 30, 2026) · NCSL: mid-decade redistricting tracker (October 30, 2026)

Verified snapshot: October 30, 2026. The explanations are written in plain language from official sources and are not legal advice. Each concept lists its sources.

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