List of American politicians who switched parties in office

The following American politicians switched parties while they were holding elected office.

Federal Senate NameStateSwitch DateCongressOld PartyNew PartyNotesRefsNew York94thConservativeRepublican Colorado104thDemocraticRepublican New York42ndRepublicanLiberal RepublicanThe Liberal Republican Party was new and short-lived. Did not seek re-election in the 1874–75 United States Senate elections.43rdLiberal RepublicanRepublicanVermont107thRepublican Independent Caucused with the Democrats after becoming an independent, giving Democrats a majority in the US Senate. His switch became the only time in US history that a party switch resulted in a change of party control of the Senate.Wisconsin74thRepublican Wisconsin Progressive Co-founded the Wisconsin Progressive Party and was re-elected to Senate on that ticket in 1934 and 1940.79thWisconsin Progressive Republican The Wisconsin Progressive Party was dissolved in 1946. Lost re-election to the Senate when defeated by Joseph McCarthy in the Republican primary later that same year.Connecticut/2007 (see note)110thDemocratic Independent Lieberman left the Democratic Party after losing the Democratic primary for re-election. Technically, he ran under the party named Connecticut for Lieberman but he himself never officially joined that party. He called himself an Independent Democrat after winning re-election.West Virginia118thDemocraticIndependent Manchin continued to caucus with the Democrats.Alabama103rdDemocratic RepublicanSwitch announced the day after the 1994 United States Senate elections, in which Shelby was not up for reelection, but the Republicans gained the majority in the Senate.Arizona118thDemocraticIndependent Sinema continued to caucus with the Democrats.New Hampshire106thRepublicanIndependentIndependentRepublicanPennsylvania111thRepublicanDemocratic South Carolina88thDemocraticRepublicanIllinois42ndRepublicanLiberal RepublicanThe Liberal Republican Party was new and short-lived. Lost re-election in the 1872–73 United States Senate elections to the Republican candidate.

House of Representatives NameStateDistrictSwitch DateCongressOld PartyNew PartyNotesRefsLouisiana5th108thDemocraticRepublicanMichigan3rd116thRepublicanIndependentContinued to caucus with the Republicans.IndependentLibertarianPennsylvania25th97thDemocraticRepublicanLost re-election in 1982 after being redistricted to the 4th district.New York1st99thConservativeRepublicanGeorgia9th104thDemocraticRepublicanJo Ann EmersonMissouri8th105thRepublicanIndependentEmerson was re-elected to a full term as an independent to comply with Missouri's electoral law.IndependentRepublicanNew York1st106thRepublicanDemocraticVirginia5th106thDemocratic Independent Caucused with the Republican Party.107thIndependent RepublicanTexas6th98thDemocraticRepublicanGramm resigned his seat as a Democrat on January 5, 1983, and then won a special election as a Republican on February 12, 1983.Florida2nd101stDemocratic RepublicanAlabama5th111thDemocratic Republican Later rejoined the Democratic party.Pennsylvania14th34thDemocratic Republican Galusha A. Grow: Father of the Homestead Law from Google BooksTexas4th108thDemocratic Republican Louisiana7th104thDemocratic Republican Florida10th98thDemocratic Republican Announced switch on March 17, 1984, but didn't officially switch until July 5 in order to keep his committee assignments for as long as possible.Oklahoma5th94thDemocratic Republican California3rd119thRepublican Independent Continued to caucus with the Republicans. Texas14th104thDemocratic Republican California31st106thDemocratic RepublicanSwitched parties after losing the Democratic primary for re-electionMichigan10th116thRepublicanIndependentSwitched parties during the lame duck session, three weeks before his retirement.Mississippi4th104thDemocratic RepublicanNew York26th92ndRepublicanDemocratic Michigan7th93rdRepublicanDemocratic Arkansas2nd101stDemocratic RepublicanNew York20th82ndDemocraticRoosevelt was re-elected as a Democrat.Arizona3rd98thDemocraticRepublicanDid not officially change party until the 1982 election for a term beginning January 3, 1983.Louisiana3rd104thDemocraticRepublicanNew Jersey2nd116thDemocraticRepublicanSouth Carolina2nd90thDemocraticRepublicanWatson resigned his seat as a Democrat on February 1, 1965, and then won a special election as a Republican on June 15, 1965.Pennsylvania12th46thDemocraticGreenback

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