How US Midterm Elections Actually Work

A midterm election is a general election held near the midpoint of a US president's four-year term. The name is descriptive rather than official: nothing about the presidency is on the ballot, which is precisely what defines it. Every federal election in the United States falls on the Tuesday after the first Monday in November, a date fixed by Congress in 1845 to suit an agrarian society that travelled to county seats on horseback. In 2026 that date is 3 November. Voters elect members of Congress, and in most states a large slate of governors, attorneys general, state legislators, judges, and ballot measures appears alongside them.

All 435 seats in the House of Representatives are contested, as they are every two years. In the Senate, 35 seats are up: the 33 seats of Class II, whose six-year terms began in 2021, plus two special elections in Florida and Ohio to fill the remainder of terms vacated when those senators left for executive-branch roles. Thirty-nine state and territorial governorships are also being decided. The result determines the composition of the 120th Congress, which convenes in January 2027.

The House and Senate are designed to respond to public opinion at different speeds, and midterms expose the difference. The entire House turns over every two years, so it swings hard and fast with the national mood. The Senate is deliberately insulated: senators serve six years, and the chamber is split into three staggered classes so that only about a third of it faces voters in any given cycle. That means a party can win a decisive national victory and still fail to take the Senate, simply because the particular seats up that year happen to sit in unfavourable states. Which class is up is fixed by the calendar, not by strategy, and it shapes what is realistically winnable long before campaigning begins.

The most reliable pattern in American politics is that the party holding the White House loses House seats at the midterms. It has happened in almost every midterm since the Civil War, with only a handful of exceptions. Political scientists offer several overlapping explanations: presidential coattails that lifted marginal candidates two years earlier are absent; voters who are unhappy have a clearer target than voters who are satisfied, so turnout skews toward the opposition; and a president's governing choices have by then produced concrete losers as well as winners. Midterm turnout is also consistently lower than in presidential years, which amplifies the effect of an energised minority.

A president cannot be removed at the midterms, but their ability to govern can be. Congress controls appropriations, confirms appointments, and holds subpoena power, so a chamber flipping to the opposition typically ends a legislative agenda and begins an oversight one. The state-level results matter at least as much and get far less attention: governors and legislatures elected now will draw or defend district maps, administer the 2028 presidential election, and set policy on education, healthcare, and policing for millions of people. Midterms are the mechanism by which a system that only elects a president every four years still answers to voters in between.