5.9 Congressional Elections

Candidates first compete in a primary election to win their party's nomination, then face the other party's nominee in the general election in November. States set the primary rules: many use open or closed primaries (5.8), a few let parties pick some nominees through conventions or caucuses, and California and Washington use a top-two primary in which all candidates share one ballot. All 435 House seats are on the ballot every two years. Senators serve six-year terms in three staggered classes, so about a third of Senate seats are up in each election.

Midterm elections are held halfway through a president's term. Turnout is lower than in presidential years (5.2), and the president's party usually loses seats in Congress in midterms, partly because voters use the election to check the president and partly because the president's most enthusiastic supporters are less likely to turn out without the president on the ballot.

Incumbents, the people already in office, win reelection most of the time. In most recent elections, more than 90 percent of House incumbents running again have won, and Senate incumbents have typically won at somewhat lower but still high rates. Reasons include:

• Name recognition: voters already know the incumbent from years of news coverage and local events.
• Casework: incumbents and their staff help constituents with problems like lost Social Security checks or veterans' benefits, building goodwill.
• Pork and credit-claiming: members bring federal projects home and take credit for them.
• Franking privilege: members can send official mail to constituents at government expense, within limits.
• Fundraising: donors, especially PACs, prefer to give to likely winners, so incumbents usually raise far more than challengers.
• Safe districts: redistricting and partisan sorting have created many districts that reliably favor one party, so the only real competition is in the primary.
• Weak challengers: strong potential candidates often wait for an open seat instead of taking on an incumbent.

Senate incumbents face tougher races than House members for several reasons. A state is usually more diverse than a single House district, and states can't be gerrymandered. Senate races draw more media attention and well-funded, well-known challengers, such as governors or House members. And a six-year term gives more time for an incumbent's votes to become an issue.

Supporters say high reelection rates reflect experienced, responsive members whom voters like. Critics say they reduce competition and accountability, and that safe seats push members to focus on primary voters, who tend to hold stronger ideological views, which feeds polarization (2.3). Proposals like term limits for members of Congress come out of this debate; the Supreme Court ruled in 1995 that states can't impose term limits on their own members of Congress.