Congressional districts are the geographic areas within a state that each elect one member to the U.S. House of Representatives. Districts are reallocated among states after every decennial census, and how state legislatures draw them shapes representation, party control, and incumbency.
A congressional district is the slice of a state that elects one representative to the House. The U.S. uses single-member districts, so each district sends exactly one person to Congress, and the candidate with the most votes wins the whole seat. The House has 435 seats total, and how many districts each state gets depends on its population, recounted every ten years by the census. That recount triggers reapportionment (states gaining or losing seats) and then redistricting (states redrawing the lines).
Here's the part AP Gov cares about most. District lines are not neutral. In most states, the state legislature draws them, which means the party in power gets to pick its own voters before the voters pick their representatives. That's why districts connect directly to gerrymandering, incumbency advantage, and landmark Supreme Court cases like Baker v. Carr (one person, one vote) and Shaw v. Reno (race can't be the predominant factor in drawing lines).
Congressional districts sit at the intersection of two units. In Unit 2 (Topic 2.2, LO 2.2.A), districts explain why the House works the way it does. House members represent small, local constituencies and face election every two years, which makes them more responsive to local interests than senators, who represent entire states. In Unit 5 (Topic 5.9, LO 5.9.A), districts drive election outcomes. The CED specifically names incumbency advantage as a factor in congressional elections, and safely drawn districts are a big reason House incumbents almost always win. If you understand how district lines get drawn and who benefits, you can explain a huge chunk of why Congress looks and behaves the way it does.
Keep studying AP Gov Unit 2
Redistricting (Unit 5)
Redistricting is the process that creates congressional districts. After each census, states redraw their district maps to reflect population shifts. The 2015 SAQ on Bush v. Vera started exactly here, with Texas gaining three districts after the 1990 census and redrawing its lines.
Gerrymandering (Unit 5)
Gerrymandering is redistricting with an agenda. When the party drawing the map packs or cracks the other side's voters, it can win more seats than its vote share would suggest. Districts are the canvas; gerrymandering is the painting.
Census (Unit 5)
The decennial census is the trigger for everything. It determines how many of the 435 House seats each state gets, which forces redistricting every ten years. No census, no reapportionment, no new maps.
Structures and Powers of Congress (Unit 2)
Districts explain the House's personality. Small constituencies and two-year terms keep representatives laser-focused on local concerns, which is a built-in contrast with the Senate's statewide, six-year perspective. That design difference shapes the whole policymaking process under LO 2.2.A.
Congressional districts show up in multiple-choice questions about reapportionment, incumbency advantage, and the House versus Senate comparison, and they're a recurring FRQ topic. The 2015 SAQ used Bush v. Vera, where Texas gained three districts after the 1990 census and the legislature's redrawn map got challenged, so be ready to apply Shaw v. Reno and Baker v. Carr to redistricting scenarios. Quantitative analysis FRQs also love election data, like the 2025 question comparing congressional results to presidential results by state. You should be able to explain how district lines affect who wins, why House incumbents rarely lose, and why the president's party tends to lose House seats in midterms.
A congressional district is just the geographic area that elects one House member. Gerrymandering is the strategic manipulation of those district boundaries to favor a party or group. Every state has congressional districts; not every district is gerrymandered. On the exam, use 'district' when describing the structure of House representation and 'gerrymandering' only when the question involves drawing lines for political advantage.
Each congressional district elects exactly one of the 435 members of the House, and the number of districts per state is based on population from the decennial census.
After each census, seats are reapportioned among the states, and state legislatures (in most states) redraw district lines through redistricting.
Because the party controlling a state legislature usually draws the map, districts can be gerrymandered to lock in seats and protect incumbents.
Baker v. Carr established 'one person, one vote,' requiring districts to have roughly equal populations, and Shaw v. Reno ruled that race cannot be the predominant factor in drawing district lines.
Small districts and two-year terms make House members more responsive to local interests than senators, a structural difference LO 2.2.A asks you to explain.
District design is one reason incumbency advantage is so strong in House elections, a factor the CED names directly in LO 5.9.A.
It's a geographic area within a state that elects one member to the U.S. House of Representatives. There are 435 districts nationwide, divided among the states by population after each decennial census.
No. Districts are apportioned by population, so populous states like California and Texas have dozens while the smallest states have just one. The total is fixed at 435, so when one state gains a seat after the census, another loses one.
The district is the thing; redistricting is the process of redrawing it. States redistrict after every census to account for population changes, like Texas did after gaining three districts following the 1990 census (the setup for Bush v. Vera).
No. Senators represent their entire state, and every state gets exactly two regardless of population. Only House members represent districts, which is why House seats shift with the census while Senate seats never do.
When legislators draw districts packed with their party's voters, the general election becomes nearly automatic for the incumbent. That's a major reason House incumbents win reelection at extremely high rates, a factor the CED lists under LO 5.9.A.