The United States (US) holds presidential elections every four years, but elections for Congress take place every two years. Those that occur halfway through a president’s term are known as the midterm elections.

On 3 November, Americans will elect all 435 voting members of the House of Representatives, along with 35 of the 100 members of the Senate, including two special elections.

A number of state governorships and other state and local positions will also be contested. The congressional elections matter most for the balance of national political power because Congress is the legislative branch of the federal government and exercises authority over taxation, federal spending, legislation, and the oversight of the executive.

Congress consists of two chambers with different responsibilities and electoral arrangements. The House of Representatives has 435 voting members, each serving a two-year term, meaning that the entire chamber is elected every two years.

The Senate has 100 members, two from each state, who serve six-year terms, with approximately one-third of that chamber facing election every two years.

The House plays a particularly important role in initiating taxation legislation, approving government spending legislation, and conducting investigations into the executive.

The Senate shares legislative authority with the House but also holds important powers over the confirmation of presidential appointments, including federal judges, senior administration officials, and justices of the Supreme Court.

For most major legislative proposals to become law, both chambers must approve the same legislation before it is submitted to the president for signature.

The significance of this arrangement is that winning the presidency does not give an American political party unrestricted authority to govern.

The constitutional system deliberately divides political power between the executive and legislature, and between the two chambers of Congress.

A president whose party controls both chambers is generally better positioned to pass legislation than one whose opponents control either chamber.

The midterm elections therefore represent an important opportunity for American voters to change the balance of political power without changing the president.

Why the 2026 midterms are especially important

Trump entered his second presidency in January 2025 with the Republican Party controlling the White House, the House of Representatives, and the Senate.

This arrangement, known as unified government, has provided his administration with an important political advantage in advancing its legislative programme.

Republicans hold 53 of the 100 Senate seats, while their majority in the House of Representatives is considerably narrower.

That means relatively small changes in electoral support across a limited number of congressional districts could alter the balance of power in the House and fundamentally change the political circumstances under which Trump governs during the final two years of his presidency.

This is an exclusive article by The Common Sense. Read more here.