US midterms: Can Congress override disputed election results?

Some of Tuesday’s U.S. midterm contests could take weeks to resolve due to recounts and legal battles. Ultimately, however, the Senate and House of Representatives determine who holds each seat, an authority that may prove crucial if control of Congress hinges on a small number of tight races.

Although federal elections are administered by individual states and certified by state election leaders, the U.S. Constitution designates each house of Congress as "the judge of the elections, returns and qualifications of its own members," giving legislators the ultimate authority whenever a House or Senate outcome is disputed.

Nearly six years after supporters of President Donald Trump attacked the U.S. Capitol on January 6, 2021, as Republicans attempted to overturn his 2020 defeat to Democrat Joe Biden, analysts suggest that closely contested races could trigger legal challenges starting at the state level while the two parties battle for congressional power.


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"Those within the recount or contest margin of error – the candidates, outside groups and the administration – will fight those tooth and nail," said Victoria Bassetti, senior advisor at States United Democracy Center, a nonprofit group focused on protecting free, fair and secure elections.

Litigation surrounding elections has surged following the 2000 U.S. Supreme Court ruling that decided the presidential contest between Republican George W. Bush and Democrat Al Gore. A review conducted by UCLA law professor Rick Hasen identified a record 756 lawsuits during the 2023–2024 election cycle—a 14.3% increase compared to 2019–2020 and roughly three times the volume seen prior to 2000.

Challenging election results

Candidates as well as current lawmakers can challenge the outcome of congressional races in either chamber. In the House, a defeated candidate may challenge a state-certified victory under the Federal Contested Election Act. The House Administration Committee reviews the dispute and can formally advise the full House on who should be sworn in.

In the Senate, disputes are routed to the Senate Rules Committee, which evaluates the arguments and presents recommendations to the full body. However, floor conflicts remain possible. For instance, if a sitting Republican tries to block the seating of a Democrat and launches a filibuster, Democrats might retaliate in kind or refuse to attend, denying the chamber a quorum to conduct business.

Unresolved House races would fall to the incoming Congress when it convenes in January rather than the outgoing one. That dynamic could complicate control of the chamber if multiple seats remain undecided. The new House must also organize itself and elect a Speaker. Past partisan deadlocks have occasionally left disputed seats open for prolonged periods.

"I don't think it's a good idea for people to get panicky or alarmist about it," Michigan State University law professor Brian Kalt said. "But after January 6, it would be naive to say there's no potential for shenanigans."

Since the inauguration of the first Congress in 1789, the House has handled 634 election challenges, according to its official records. Meanwhile, Senate documents show the upper chamber has faced at least two dozen such disputes since direct popular election of senators began in 1914.

Thin house and Senate margins

Both the House and Senate, currently held by Republicans with slim majorities, could flip if Democrats gain a net four seats in each chamber. All 435 House seats are up for election, whereas only about a third of the 100 Senate seats are on the ballot.

The Trump administration has already filed lawsuits regarding this election cycle, seeking to block Alaska from certifying results if Republican Senator Dan Sullivan loses and attempting to stop California from counting more than 20,000 mail-in ballots.

Senate control and empty seats

By established custom, both the House and Senate may temporarily seat candidates provisionally in contested races while legal disputes or investigations play out. However, extended courtroom litigation can delay formal certification and leave seats vacant.

In modern history, no disputed election has altered overall control of the Senate, though there have been tight situations since 1914. With up to seven races categorized as toss-ups this year, experts highlight two key instances where Senate seats remained empty for months:

• Minnesota (2008): A court fight between Democratic challenger Al Franken and Republican incumbent Norm Coleman left the seat vacant for months. It was finally decided in Franken's favor in July 2009—six months after Coleman's term had expired.
• New Hampshire (1974): An election went unresolved even longer as the Senate struggled to decide between Democrat John Durkin and Republican Louis Wyman. Conflicting state recounts produced different winners, state courts declined to intervene, and a Senate election committee reached a deadlock. The dispute dragged on until lawmakers declared the seat vacant in July 1975, leading to a September special election won by Durkin.

House in turmoil

The House has historically seen far more election challenges than the Senate. Nonpartisan analysts at Inside Elections currently rate 18 House contests as toss-ups, with additional races staying highly competitive.

Since 1789, the House has averaged slightly over five contested elections per election cycle, with the vast majority occurring during the 19th century, specifically across the Civil War, Reconstruction, Gilded Age, and early Jim Crow eras. Should Democrats secure a major wave victory, analysts note that widespread wins could make individual contested races irrelevant to overall control.

The peak occurred in 1895: after Republicans won a landslide fueled by public outrage over a severe economic downturn, a record 38 House races were contested. According to House records, many of those seats remained unresolved for more than two years after the election.

(With inputs from agency)