The U.S. House of Representatives and the U.S. Senate hold the final authority to determine who is seated in their respective chambers following contested elections. While federal elections are administered and certified by individual states, the U.S. Constitution designates each chamber as the judge of the elections and qualifications of its own members. This power could prove decisive if a small number of contested races determine which party controls Congress after the upcoming midterm elections.
The potential for federal intervention follows a period of increased election-related litigation. According to data compiled by UCLA law professor Rick Hasen, there were a record 756 election cases during the 2023-2024 cycle, a 14.3% increase from 2019-2020. Victoria Bassetti, a senior advisor at the States United Democracy Center, stated that candidates, outside groups, and the administration are likely to intensely litigate any races that fall within a recount or contest margin of error.
Procedurally, a losing House candidate can challenge a state-certified result under the Federal Contested Election Act, with the House Administration Committee making a recommendation to the full chamber. In the Senate, challenges are referred to the Senate Rules Committee. The Trump administration has already engaged in election-related litigation, suing to block Alaska from certifying results if Republican Senator Dan Sullivan loses and seeking to prevent California from counting over 20,000 mail-in ballots.
The outcome of these procedures affects the 435 House seats and the 33 Senate seats up for election, as well as the balance of power for the incoming Congress. Republicans currently control both chambers by slim margins, and Democrats would need a net gain of four seats in each chamber to take control. If results remain unresolved when the new Congress convenes in January, the new House must still organize and elect a speaker, a process that can be complicated by vacant seats.
For voters and candidates in states like Alaska and California, these legal challenges and congressional reviews can lead to significant delays in representation. In 2008, a Minnesota Senate seat remained vacant for six months after the term began while Democrat Al Franken and Republican Norm Coleman litigated the results. A similar 1974 New Hampshire race resulted in a seat remaining vacant until September 1975. During such periods, the affected residents lack a seated representative.
Partisan gridlock can further extend these vacancies, as the process for seating members in contested races involves internal chamber votes that can be subject to filibusters or quorum boycotts. While the House has dealt with 634 contested elections since 1789, a high volume of challenges—such as the record 38 contests in 1895—can leave seats undecided for more than two years. The new Congress is scheduled to convene in January, at which point the incoming House and Senate will take over any pending election challenges.