Third-party and independent members of the United States Congress

Third-party and independent members of the United States Congress are generally rare. Although the Republican and Democratic parties have dominated U.S. politics in a two-party system since 1856, some independents and members of other political parties have also been elected to the House of Representatives or United States Senate, or changed their party affiliation during their term.

Senate ImageSenatorStateTermNotesAngus KingMaine2013–presentElected as an independent; caucuses with the DemocratsBernie SandersVermont2007–presentElected as an independent; caucuses with the Democrats; Democratic Party member from 2015–2016 and 2019–2020 while running for PresidentJoe ManchinWest Virginia2010–2025Elected as a Democrat, switched to independent in 2024Kyrsten SinemaArizona2019–2025Elected as a Democrat, switched to independent in 2022Joe LiebermanConnecticut1989–2013Re-elected on the Connecticut for Lieberman ticket after losing the 2006 Democratic nominationDean BarkleyMinnesota2002–2003Appointed for Independence Party of MinnesotaJim JeffordsVermont1989–2007Switched from Republican to independent in 2001Bob SmithNew Hampshire1990–2003Switched from Republican to independent in 1999 but switched back to Republican in 2000 James L. BuckleyNew York 1971–1977Elected as a Conservative, lost re-election as a Republican in 1976 Harry F. Byrd Jr.Virginia1965–1983Switched from Democratic to independent in 1970Wayne MorseOregon1945–1969Switched from Republican to independent in 1953, then to Democratic in 1955John E. MillerArkansas1937–1941Elected as an independent, served as DemocraticErnest LundeenMinnesota1937–1940Elected as Farmer-LaborGeorge W. NorrisNebraska 1913–1943Switched from Republican to independent in 1936Elmer Austin BensonMinnesota1935–1936Elected as Farmer-LaborRobert M. La Follette Jr.Wisconsin1925–1947Switched from Republican to Progressive in 1934, then back to Republican in 1946Magnus JohnsonMinnesota1923–1925Elected as Farmer-LaborHenrik ShipsteadMinnesota1923–1947Elected as Farmer-Labor, switched to Republican in 1940Miles PoindexterWashington1911–1923Switched from Republican to Progressive in 1912, switched back to Republican in 1915Joseph M. DixonMontana1907–1913Switched from Republican to Progressive in 1912Henry HeitfeldIdaho1897–1903Elected as a PopulistWilliam Alexander HarrisKansas1897–1903Elected as a PopulistHenry Moore TellerColorado1876–1909Switched from Republican to Silver Republican in 1896, then to Democratic in 1903Fred DuboisIdaho1891–1897Switched from Republican to Silver Republican in 1896Frank J. CannonUtah1896–1899Switched from Republican to Silver Republican in 1896Richard F. PettigrewSouth Dakota1889–1901Switched from Republican to Silver Republican in 1896Lee MantleMontana1895–1899Switched from Republican to Silver Republican in 1896John P. JonesNevada1873–1903Switched from Republican to Silver in 1895, then back to Republican in 1901William Morris StewartNevada1887–1905Switched from Republican to Silver in 1893, then back to Republican in 1901William V. AllenNebraska1893–1901Elected as a PopulistJames H. KyleSouth Dakota1891–1901Elected as a PopulistMarion ButlerNorth Carolina1895–1901Elected as a PopulistWilliam A. PefferKansas1891–1897Elected as a PopulistHarrison H. RiddlebergerVirginia1883–1889Elected as a ReadjusterWilliam MahoneVirginia1881–1887Elected as a ReadjusterDavid DavisIllinois1877–1883Elected as an independentNewton BoothCalifornia1875–1881Elected as an Anti-Monopolist, served as an Independent RepublicanOrris S. FerryConnecticut1867–1875Elected as a Liberal Republican in 1872Morgan C. HamiltonTexas1870–1877Switched from Republican to Liberal Republican in 1872, switched back to Republican in 1875Charles SumnerMassachusetts1851–1874Elected as Free Soil Democratic in 1851, became a Republican in 1855, then became a Liberal Republican in 1872David T. PattersonTennessee1866–1869Elected as a Unionist in 1866, became a Republican by 1867Joseph S. FowlerTennessee1866–1871Elected as an Unconditional Unionist in 1866, became a Republican by 1867John CreswellMaryland1865–1867Elected as an Unconditional Unionist in 1864Benjamin Gratz BrownMissouri1863–1867Elected as a Union Emancipationist in 1863, became a Radical Unionist (Republican) by 1865Peter G. Van WinkleWest Virginia1863–1869Elected as a Unionist in 1863, became a Republican by 1867Reverdy JohnsonMaryland1863–1868Elected as a Unionist in 1863, switched to Democratic by 1865Lemuel J. BowdenVirginia1863–1864Elected as a Unionist in 1863Thomas Holliday HicksMaryland1862–1865Elected as an Unconditional Unionist in 1862Robert WilsonMissouri1862–1863Appointed as a Unionist in 1862John B. HendersonMissouri1862–1869Elected as a Unionist in 1862, became a Republican by 1865Garrett DavisKentucky1861–1872Elected as a Union Democrat in 1861, switched to Democratic by 1867John S. CarlileVirginia1861–1865Elected as a Unionist in 1861Waitman T. WilleyVirginia1861–1863Elected as a Unionist in 1861

House of Representatives ImageRepresentativeDistrictTermNotesKevin KileyCalifornia 3rd2023–presentFirst elected as a Republican, switched to independent in 2026Paul MitchellMichigan 10th2017–2021First elected as a Republican, switched to independent in 2020Justin AmashMichigan 3rd2011–2021First elected as a Republican, switched to independent in 2019 and then to Libertarian in 2020Virgil GoodeVirginia 5th1997–2009Switched from Democratic to independent in 2000, then to Republican in 2002Jo Ann EmersonMissouri 8th1996–2013First elected as a Republican, re-elected as an independent due to state law, then rejoined Republicans in early 1997Bernie SandersVermont at-large1991–2007Elected as an independentWilliam CarneyNew York 1st1979–1987Elected as a Conservative and later sat with Republicans, switched to Republican in 1985Frazier ReamsOhio 9th1951–1955Elected as an independentFranklin Delano Roosevelt Jr.New York 20th1949–1955Elected as a Liberal, re-elected as DemocraticLeo IsacsonNew York 24th1948–1949Elected from the American Labor Party ticketHarold HagenMinnesota 9th1943–1955Elected as a member of the Minnesota Farmer–Labor Party in 1942John BernardMinnesota 8th1937–1939Elected as a member of the Minnesota Farmer–Labor Party in 1936Dewey JohnsonMinnesota 5th1937–1939Elected as a member of the Minnesota Farmer–Labor Party in 1936Franck R. HavennerCalifornia 4th1937–1941, 1945–1953Elected as a Progressive, re-elected as DemocraticHenry TeiganMinnesota 3rd1937–1939Elected as a member of the Minnesota Farmer–Labor Party in 1936Thomas Ryum AmlieWisconsin 1st1935–1939Elected as a ProgressiveGerald J. BoileauWisconsin 7th1935–1939Elected as a ProgressiveRich T. BucklerMinnesota 9th1935–1943Elected as a member of the Minnesota Farmer–Labor Party in 1934Bernard J. GehrmannWisconsin 10th1935–1943Elected as a ProgressiveHarry SauthoffWisconsin 2nd1935–1945Elected as a ProgressiveGeorge J. SchneiderWisconsin 8th1935–1939Elected as a ProgressiveMerlin HullWisconsin 9th1935–1944Elected as a ProgressiveVito MarcantonioNew York 20th1935–1937, 1939–1945Elected from the American Labor Party ticket in 1938Gardner R. WithrowWisconsin 3rd1935–1939Elected as a ProgressiveHenry M. ArensMinnesota at-large1933–1935Elected as a member of the Minnesota Farmer–Labor Party in 1932Magnus JohnsonMinnesota at-large1933–1935Elected as a member of the Minnesota Farmer–Labor Party in 1932Ernest LundeenMinnesota 5th, Minnesota at-large, Minnesota 3rd1933–1937Elected as a member of the Minnesota Farmer–Labor Party in 1932Francis ShoemakerMinnesota at-large1933–1935Elected as a member of the Minnesota Farmer–Labor Party in 1932Paul John KvaleMinnesota 7th, Minnesota at-large1929–1939Elected as a member of the Minnesota Farmer–Labor Party in 1928Knud WefaldMinnesota 9th1923–1927Elected as a member of the Minnesota Farmer–Labor Party in 1922Ole J. KvaleMinnesota 7th1923–1929Elected as a member of the Minnesota Farmer–Labor Party in 1922William Leighton CarssMinnesota 8th1919–1929Elected as a member of the Minnesota Farmer–Labor Party in 1918Fiorello La GuardiaNew York 14th, New York 20th1917–1919, 1923–1933Re-elected as a Socialist in 1924, ran as a Republican in all other electionsJohn A. ElstonCalifornia 6th1915–1921Elected as a Progressive in 1915Meyer LondonNew York 12th1915–1923Elected as a SocialistWhitmell P. MartinLouisiana 3rd1915–1929Elected as a Progressive in 1914 and 1916, ran as a Democrat after thatThomas D. SchallMinnesota 10th1915–1925Elected as a Progressive in 1914 and 1916, ran as a Republican after thatCharles Hiram RandallCalifornia 9th1915–1921Elected as a ProhibitionistWalter M. ChandlerNew York 19th1913–1919 1921–1923Elected as a Progressive in 1912 and 1914, ran as a Republican after thatJames W. BryanWashington at-large1913–1915Elected as a Progressive in 1912Jacob FalconerWashington at-large1913–1915Elected as a Progressive in 1912William H. HinebaughIllinois 12th1913–1915Elected as a Progressive in 1912Willis James HulingsPennsylvania 28th1913–1915Elected as a Progressive in 1912William Josiah MacDonaldMichigan 12th1913–1915Elected as a Progressive in 1912Milton William ShrevePennsylvania 25th1913–1915, 1919–1933Re-elected as an Independent Republican in 1920Henry Wilson TemplePennsylvania 24th1913–1915Elected as a Progressive in 1912Charles M. ThomsonIllinois 10th1913–1915Elected as a Progressive in 1912William StephensCalifornia 10th1911–1917Elected as Republican in 1910, re-elected as a ProgressiveRoy O. WoodruffMichigan 10th1913–1915 1921–1953Elected as a Progressive in 1912, re-elected as a Republican in 1920Bill KentCalifornia 1st1911–1917Elected as a Republican in 1910, re-elected as an IndependentIra C. CopleyIllinois 11th1911–1923Re-elected as a Progressive in 1924, ran as a Republican in all other electionsVictor L. BergerWisconsin 5th1911–1913 1923–1929Elected as a SocialistPeter A. PorterNew York 34th1907–1909Elected as an Independent RepublicanCaldwell EdwardsMontana at-large1901–1903Elected as a PopulistThomas L. GlennIdaho at-large1901–1903Elected as a PopulistJohn Wilbur AtwaterNorth Carolina 4th1899–1901Elected as a PopulistWilliam NevilleNebraska 6th1899–1903Elected as a PopulistEdgar WilsonIdaho at-large1895–1897