The 2026 U.S. midterm elections are in their final stretch. Early voting has been underway for weeks ahead of the November 3 vote, when Americans will elect the full House of Representatives, a third of the Senate and governors across the country — a contest Reuters walked through in an explainer published Monday.

The scale is record-breaking. As of October 12, $3.8 billion had been spent on political advertisements, according to AdImpact, with the heaviest spending in battleground Senate races in Texas, Ohio and Michigan. Elon Musk alone has spent about $366 million supporting Republicans, according to campaign finance records. If turnout resembles the last midterms in 2022, more than 100 million people will cast ballots.

The arithmetic is tight in both chambers. Republicans hold the House 218–214, with two vacancies and one independent caucusing with them; Democrats need a net gain of four seats to take control. In the Senate, Republicans hold a 53–47 majority and Democrats likewise need a net gain of four, with about ten races — including Maine, Ohio, North Carolina, Iowa and Georgia — likely to decide the outcome.

Midterms do not involve the president directly, but they decide how much of his agenda Congress will fund, investigate or block for the next two years. With both majorities this thin, a handful of districts and a few hundred thousand voters in the battleground states will effectively choose the balance of power in Washington.