Congressional Elections

All 435 seats in the House are up for election every two years, in even-numbered years, on the same November date as presidential elections. Senators serve six-year terms in three staggered classes, so about one third of the Senate is elected every two years. Elections in years without a presidential race are called midterms, and the President's party has lost House seats in most of them. Senators were chosen by state legislatures until the Seventeenth Amendment, ratified in 1913, required direct popular election.

A representative must be at least 25, a citizen for seven years, and an inhabitant of the state, though not necessarily the district. A senator must be at least 30, a citizen for nine years, and an inhabitant of the state. States run the elections, set primary rules, draw House districts, and certify results, subject to federal law and the Constitution. Each chamber is the final judge of its members' elections and qualifications. Most states nominate candidates through party primaries, while a few, including California and Washington, use top-two primaries, and Alaska uses a top-four primary with ranked-choice general elections.

When a House seat becomes vacant, the Constitution requires a special election, so the seat may stay empty for months. When a Senate seat becomes vacant, most states let the governor appoint a temporary replacement until a special election. Incumbents win reelection at very high rates, typically above 90 percent in the House, in part because most districts are drawn to favor one party. The 2026 midterm elections are scheduled for November 3, 2026.