In short: midterm elections are the federal elections held halfway through a president's four-year term. They decide who controls Congress for the next two years, which makes them a referendum on the president even though the president is not on the ballot. The 2026 midterms take place on Tuesday, November 3, 2026.
What is on the ballot
| Office | What is elected in 2026 |
|---|---|
| House of Representatives | All 435 seats (two-year terms) |
| Senate | About a third of the 100 seats, plus any special elections |
| Governors | 36 states |
| State and local | Legislatures, mayors, judges, ballot measures |
Because every House seat is up, a swing of a few dozen districts can change the majority.
What midterms are for
The US Constitution staggers elections on purpose. Midterms give voters a chance to:
- Check the president. A Congress controlled by the other party can block legislation and slow confirmations.
- Renew the House. Representatives face voters every two years, keeping them close to public opinion.
- Shape state government. Governors and legislatures elected in midterms often draw district maps and run future elections.
Why the president's party usually loses ground
In most midterms since World War II, the president's party has lost House seats. Typical reasons are lower enthusiasm among the president's voters, higher turnout among opponents and a backlash against whatever has gone wrong in the first two years. It is a pattern, not a law: the outcome still depends on the map, candidates and events.
How prediction markets price the midterms
On a prediction market, you can trade questions such as "Which party will control the House?" or "Will a given Senate seat flip?". A share at 0.65 means traders see about a 65% chance. Unlike polls, which measure what voters say today, prices fold in the map, fundraising and history. Our guide to polls vs prediction markets explains the difference, and Polymarket's political markets shows the kinds of questions listed.
Remember that:
- Control of each chamber is a separate market from individual races.
- Thin markets on local races can swing on a single news story.
- Results are certified by states, which can take time in close races; read each market's resolution source.
How to follow the 2026 midterms
- Check your state's election office for registration and voting dates.
- Look at polling averages rather than single polls.
- Use market prices as a second opinion, not a forecast you must trust.
Prediction markets involve risk. Check where Polymarket is legal before trading, and only use money you can afford to lose.
Next step
In the United States, the regulated route is the Polymarket US app. Read our guides on signing up and depositing to get started, start small and only use money you can afford to lose.