Voters may wait weeks to learn which party controls Congress

Denver residents and other voters in Colorado will likely wait several days to learn which party holds the majority in the U.S. House and Senate following Tuesday's election. The Associated Press will determine control of both chambers only after final vote counts are verified in all districts.

The House requires 218 seats for a majority. Republicans currently hold 219 seats, though two vacancies exist. In the Senate, Democrats need 51 seats or 50 seats with Vice President JD Vance casting a tiebreaking vote for the Republicans. The GOP currently leads 53-47.

Historical data suggests a significant delay. In the 2022 midterm elections, the AP announced Senate control four days after Election Day and House control eight days later. During the 2024 presidential cycle, Senate results were finalized the day after the vote, while House results took eight days.

Counting delays often stem from mail-in ballots and voting systems in specific states. California, the most populous state, saw half of its votes counted after Election Day in 2022. Thousands of mail ballots are typically dropped off on election day itself.

Alaska and Maine, which have key Senate races, use ranked choice voting. This system can extend the counting process if no candidate receives more than 50% of first-choice votes. In such cases, the candidate with the fewest votes is eliminated, and their ballots are redistributed to voters' second choices.

The AP will not project winners. It will declare a victor only when it determines that trailing candidates cannot close the gap in any possible scenario.