2020 United States Senate elections

The 2020 United States Senate elections were held on November 3, 2020, with the 33 class 2 seats of the Senate contested in regular elections. Of these, 21 were held by Republicans, and 12 by Democrats. The winners were elected to 6-year terms from January 3, 2021, to January 3, 2027. Two special elections for seats held by Republicans were also held in conjunction with the general elections: one in Arizona, to fill the vacancy created by John McCain's death in 2018; and one in Georgia, following Johnny Isakson's resignation in 2019. These elections ran concurrently with the 2020 United States presidential election in which incumbent president Donald Trump lost to Democratic nominee Joe Biden. In the 2014 United States Senate elections, the last regularly scheduled elections for Class 2 Senate seats, the Republicans won nine seats from the Democrats and gained a majority, which they continued to hold after the 2016 and 2018 elections. Before the elections, Republicans held 53 seats, Democrats held 45 seats, and independents caucusing with the Democrats held two seats, neither of which were up for re-election. Including the special elections in Arizona and Georgia, Republicans defended 23 seats, and the Democrats defended 12. In this election, the Democratic Party made a net gain of three Senate seats and the vice presidency, giving them a majority for the first time since 2014, albeit by a narrow 50–50 margin. Democrats unseated four Republicans in Arizona, Colorado, and both elections in Georgia – while Republicans flipped a seat in Alabama; however, Democrats under-performed expectations overall; despite record-breaking turnout and fund-raising efforts, they failed to flip several seats that were considered competitive, and lost many races by much larger margins than expected. Except in Maine, the winning party in every Senate election was the winning party in the state's presidential election. Due to election laws in Georgia that require candidates to win at least 50% of the vote in the general election, the state's regularly scheduled and special Senate elections were decided in run-off elections on January 5, 2021. After the November general election, Republicans held 50 seats, while Democrats held 48 and the vice presidency, so sweeping both races was crucial for Democrats to attain a majority. They succeeded in doing so, and the partisan balance in the Senate became tied for the third time in history, after the results in the 1880 elections and the 2000 elections. Vice President Kamala Harris's tie-breaking vote gave Democrats control of the chamber by the smallest margin possible after the new administration took office. This marked the first time since 1980 that either chamber of Congress flipped partisan control in a presidential election year, and the first time Democrats did so since 1948. This was the fourth presidential election cycle in a row, after 2008, 2012 and 2016, where Democrats made gains.