Coin Flips, Empty Seats and a Tie in the Senate: The Strangest Ways Control of Congress Could Be Decided

PrecedentThe 2001 Senate opened 50–50 and changed hands twice in its first five months. Democrats held it for 17 days with outgoing Vice President Al Gore breaking ties, and Republicans took over when Dick Cheney was sworn in on January 20. The two parties adopted a power-sharing agreement (S.Res. 8) on January 5, 2001: committees were split evenly, and either leader could move to discharge a measure blocked by a tied committee vote. The 2021 Senate repeated the arrangement with S.Res. 27, adopted February 3, 2021, after Mitch McConnell held up the organizing resolution seeking assurances on the filibuster. Kamala Harris cast 33 tie-breaking votes as vice president.

2026The Senate is 53 Republicans, 45 Democrats and two independents who caucus with Democrats (Kalshi's tracker, Oct. 21). If Democrats gain three seats net, the chamber is 50–50 and Vice President JD Vance, who had cast eight tie-breaking votes as of August 20, keeps Republicans in control. A power-sharing deal isn't automatic; it would have to be negotiated. See Senate Math 101.

PrecedentOn January 5, 2021, two days after the new Congress convened, Georgia held two Senate runoffs. Jon Ossoff and Raphael Warnock both won, which put the Senate at 50–50 and gave Democrats control through the vice president's tie-breaking vote.

2026Georgia still requires a majority, and a December 1 runoff is on the calendar. But Georgia Libertarians ended their 2026 ballot-access drive in July, leaving the major races largely two-way, which makes a runoff unlikely. Ossoff led by about 10 points in FiftyPlusOne's average (accessed Oct. 29). Louisiana is the more likely source of overtime this year: its U.S. House races use an all-party ballot on November 3, with a December 12 runoff wherever no one tops 50%. See Georgia's 50% rule.

PrecedentOn May 24, 2001, Vermont Sen. Jim Jeffords left the Republican Party to become an independent who caucused with Democrats. The Senate convened with a Democratic majority on June 6. The Senate Historical Office calls it the first time party control changed formally in the middle of a two-year Congress. The next year, Jim Talent's November 2002 win in a Missouri special election technically handed control back to Republicans, but Congress adjourned before it made any practical difference.

2026California Rep. Kevin Kiley left the Republican Party on March 9, 2026, but still caucuses with House Republicans and kept his committee seats. In a narrow House or Senate, one defection or one member declining to caucus can matter more than a seat won on election night.

PrecedentDemocrats' 50 seats in 2021 included independents Angus King and Bernie Sanders, who both caucus with Democrats, so their choice was essential to that majority. Committee seats are given out through party caucuses, which is why an independent usually picks a side. When Kyrsten Sinema left the Democratic Party in 2022, Democrats let her keep her committee assignments.

2026Nebraska's Dan Osborn says he would "caucus with everybody" (Roll Call, Sept. 24). His race with Republican Pete Ricketts is about even: PollCheck had Ricketts ahead by 0.5 as of October 29, and FiftyPlusOne had him ahead by 0.3. In Montana, independent Seth Bodnar told Montana Public Radio he would not be "a foot soldier for either" party. How a non-aligned senator would actually get committee seats is untested. See how independents could decide 2026.

PrecedentNorm Coleman's term ended in January 2009 while his recount and court fight with Al Franken continued. The Senate didn't seat anyone, and Minnesota had one senator until Franken was sworn in on July 7, 2009, which we count as 185 days. In New Hampshire, the 1974 race went from Louis Wyman by 355 votes, to John Durkin by 10 after a recount, to Wyman by 2 after a state commission review. The Senate never resolved it. On July 30, 1975, it declared the seat vacant, 71–21, and Durkin won a new election on September 16.

2026Terms end at noon on January 3 under the 20th Amendment, and January 3, 2027 falls on a Sunday. A close race in a state with an automatic recount could still be in dispute by then; Nebraska and South Carolina recount automatically at margins up to 1%. Thresholds by state are in our recount thresholds guide.

PrecedentArticle I, Section 5 makes each chamber "the judge of the elections, returns and qualifications of its own members." In Indiana's 8th District, which became known as the "Bloody Eighth," the state certified Republican Rick McIntyre and a recount showed him ahead by 418 votes. The Democratic House declined to seat him and ran its own count, which put Democrat Frank McCloskey ahead by 4. On May 1, 1985, the House seated McCloskey, 230–195, and Republicans walked out. In North Carolina's 9th District in 2018, the state board refused to certify a 905-vote result after allegations that a campaign operative ran an illegal absentee-ballot operation, and it ordered a new election. Republican Dan Bishop won it on September 10, 2019. In Iowa's 2nd District, a six-vote race went to the House under the Federal Contested Elections Act in 2020. Mariannette Miller-Meeks was seated provisionally, and Rita Hart dropped her challenge on March 31, 2021.

2026The Contested Elections Act covers only the House, and a challenger must file within 30 days after the result is declared. The Senate handles disputes under its own rules. One 2026 detail: a Campaign Legal Center guide notes that Texas excludes U.S. House and Senate races from its state election-contest process, so a fight over a Texas federal seat would end up in Congress. Supporters of the current system say Article I, Section 5 rightly leaves the last word to elected members. Critics say it lets a majority vote on its own size.

PrecedentLouisiana Rep.-elect Luke Letlow died on December 29, 2020, days before he was to be sworn in. His widow, Julia Letlow, won the special election on March 20, 2021. In the Senate, Missouri voters elected Gov. Mel Carnahan weeks after he died in an October 2000 plane crash. The acting governor appointed his widow, Jean Carnahan, who served until November 2002.

2026The two chambers fill vacancies differently, and that can change the math. A House vacancy stays empty until a special election, because the Constitution provides only for "writs of election." Senate vacancies can be filled by appointment. Ballotpedia counted 46 states allowing a governor to appoint after Oregon joined in June 2025. A Congressional Research Service overview lists Arizona, Montana and North Carolina as requiring an appointee of the same party, and Hawaii, Maryland, Utah, West Virginia and Wyoming as having the governor choose from the party's nominees. Everywhere else, a governor of the other party could change the Senate count. The House currently has two vacancies (TX-23 and FL-20) that have been open since April. For deaths and withdrawals before Election Day, see our ballot replacement guide.

PrecedentIn Maine's 2nd District in 2018, Republican Bruce Poliquin led the first round 46.4% to 45.5%. After the ranked-choice tabulation, completed November 15, Democrat Jared Golden won 50.53% to 49.47%. A federal judge refused Poliquin's request to stop the count.

2026Alaska and Maine use ranked-choice voting for Senate and House races. Alaska will tabulate rankings on November 18 if no one tops 50%, with certification targeted for November 25, and voters are also deciding Ballot Measure 2, which would repeal the system. Six declared write-in candidates in Maine's Senate race mean ranked-choice rules apply there if neither Susan Collins nor Troy Jackson gets a majority. Maine officials say ranked-choice counts take several days. See Alaska's ranked-choice math.

PrecedentThe Speaker is the first order of business in a new Congress. Members-elect vote before they are sworn in, and the winner needs a majority of the votes cast for a person by name, so "present" votes and empty seats lower the bar. The 1855–56 contest took 133 ballots over two months. Kevin McCarthy needed 15 ballots and was elected early on January 7, 2023. In 1985, the Speaker vote took place while Indiana's 8th District seat was still empty.

2026A House race still being recounted or contested on opening day could leave that seat out of the Speaker vote. One calendar quirk: January 3, 2027 is a Sunday. The 20th Amendment fixes terms to begin at noon that day, but it lets Congress set a different date for its first meeting by law. See how the House will elect a Speaker.

PrecedentSen. Lisa Murkowski lost Alaska's 2010 Republican primary to Joe Miller and ran as a write-in. Roll Call reported that she became the first person elected to the Senate by write-in since 1954. Her count stood at 100,868 to Miller's 90,448 as of November 17. Misspelled ballots were counted for her when the voter's intent was clear, including 8,153 write-ins that Miller had challenged. Alaska certified her win on December 30.

2026We found no competitive write-in campaign in a battleground race. In Maine, though, write-ins have a technical effect. Votes for anyone who didn't file as a declared write-in, including former nominee Graham Platner, are treated as blank. Alaska's Senate ballot also lists a second candidate named Dan Sullivan (Dan J. Sullivan) alongside the incumbent, according to Newsweek.

PrecedentIn Virginia's 94th House of Delegates district in 2017, a court review of one ballot turned a one-vote Democratic lead into a tie at 11,607 each. On January 4, 2018, officials put each candidate's name in a film canister, drew one from a bowl, and Republican David Yancey won. That kept Republicans in control of the chamber; a Democratic win would likely have meant a 50–50 split. Alaska broke a tied 2006 state House primary with a coin toss.

2026We found no U.S. House or Senate general election ever settled by lot, but the laws are in place. Virginia's statute explicitly applies drawing by lot to members of Congress. Kansas uses lot for state and national offices unless a federal statute applies. Texas holds a recount before drawing lots in some races and calls a new election in others. Maine has started automatic recounts in ties since 2025, though for U.S. House and Senate seats its law defers to the Constitution. NCSL counts 28 states that use lot to break ties for state legislative seats. Because of Article I, Section 5, the House or Senate would still have the final word on any winner chosen this way.