Midterms, in maps and charts: What’s at stake this Tuesday and where Trump stands

U.S. midterm elections are elections held halfway through a presidential term. They do not choose the president, but they decide control of Congress and many state offices. The results determine whether the president can advance legislation, budgets and appointments easily during the term’s final two years.

They occur two years after the presidential election because House elections happen every two years, and all 435 House seats are contested each time. Senate elections are staggered, so only about one-third of the 100 Senate seats are normally on the ballot. Governors and other state and local officials may also be elected.

This election is therefore a major political checkpoint for Donald Trump. Polls show 37% approval, while Democrats are favored for the House. If voters shift power, the final two years of Trump’s term could feature a much more confrontational Congress, especially if Democrats control one or both chambers.

This election covers national, state and local government. At the federal level, voters choose all 435 members of the House of Representatives. They also choose 35 Senate seats, including two special elections in Florida and Ohio. The Senate has 100 seats, but its terms are staggered, so only some are contested each cycle.

At the state level, voters elect governors in 36 states. The governorships are evenly divided before voting, with 18 held by Democrats and 18 by Republicans. State legislative races are also taking place in many states, although the article does not give a total number of those seats.

The ballot extends beyond those offices. Voters will choose local officials, including city council members, school board members and district attorneys. These elections can affect taxes, education, policing and civil rights. Together, the contests decide power at several levels, not just in Washington.

If Democrats gain control of either chamber, they can make Trump’s agenda harder to carry out. Congress controls legislation and budgets, while the Senate has a key role in confirming judges and senior officials. A chamber controlled by the opposition can refuse to advance measures or use its authority to delay them.

The House could block or reshape spending bills and other legislation. The Senate could block presidential appointments, including judges and senior officials, and prevent measures from advancing. Control of just one chamber would therefore force the administration to negotiate more often and accept compromises.

Control of both chambers would give Democrats the strongest position. The article says they could mount a more aggressive opposition by blocking legislation, budgets and appointments during Trump’s final two years. Republicans currently hold both chambers, but Democrats are favored to win the House and are competing closely for the Senate.

The difference comes from each chamber’s current balance and its majority threshold. The House has 435 seats, and 218 are needed for control. Republicans currently hold only a narrow advantage, so four Democratic pickups would be enough to move the chamber across that threshold.

The Senate has 100 seats, with two senators representing every state. Republicans currently control it, but Democrats need a net gain of four seats to take it back. A net gain means Democratic victories must exceed Republican victories by four, after accounting for the seats each party is defending.

The Senate’s map also makes the challenge different. Only 35 seats are being contested, including special elections in Florida and Ohio, and Democrats are defending seats in Georgia and Michigan. Several competitive races are in states Trump won in 2024, so Democrats must gain Republican seats while protecting vulnerable ones.

The president’s party usually loses congressional seats because midterms often become a judgment on the incumbent administration. Voters are choosing lawmakers rather than a president, so dissatisfaction with the White House can shift support toward the opposition. The article describes this as a historical pattern, not an absolute rule.

The House shows the pattern most clearly. Since World War II, the incumbent president’s party has lost House seats in 17 of 19 midterm elections. The average loss was about 27 seats. Joe Biden’s Democrats were an exception in 2022, suffering an unusually small setback.

That history helps explain why Democrats are favored now. Trump’s approval is 37%, and Democrats lead Republicans in the House polling average, 51% to 42.5%. Still, history is not a guarantee. The Senate can behave differently, and the final result depends on individual races, turnout and each party’s candidates.

House and Senate elections measure different political landscapes. Every House district votes in the same cycle, so the national mood can produce a broad swing. Senate races are statewide contests, and only 35 of 100 seats are on the ballot. The states holding those races may not reflect the country as a whole.

The article gives 2018 as the clearest example. Trump’s Republicans lost control of the House but gained Senate seats. That split result was possible because the Senate map, rather than the national vote alone, determined which contests mattered. Candidate strength and local political conditions also shape individual Senate races.

The current Senate map could again produce a different outcome. Democrats are defending seats in Georgia and Michigan, both states Trump won in 2024. They are also targeting Republican-held seats in Maine, North Carolina, Ohio, Texas and Alaska. Several targets are traditionally Republican, making the Senate contest unusually uncertain.

State and local officials make decisions that govern everyday services and rights. Governors shape state policy on abortion, voting rights, immigration and education. State legislators help write laws and budgets, while local officials manage issues closer to residents’ homes and communities.

The article names city councils, school boards and district attorneys as examples. These offices influence taxes, education, policing and civil rights. A school board can affect local education decisions, while a district attorney influences how criminal cases are pursued. The article does not assign specific powers to each office, but it stresses their combined impact.

That makes the governors’ races important even without a single national majority to win. Thirty-six states are electing governors, with 18 Democratic-held and 18 Republican-held seats currently up for election. State and local results can change policy directly, regardless of which party controls Congress.