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The Low Success Rate of Independent and Third-Party Candidates in Senate Elections


— Missouri independent candidate Craig O’Dear is running for U.S. Senate in 2018 but faces long odds of winning.

— Independent and third-party candidates tend to do poorly in most partisan elections, but they have a particularly poor track record in Senate contests. Only 11 candidates in 14 elections have ever won at least 35% of the vote while facing a Democrat and a Republican.

— Many successful independent and minor-party candidates had prior electoral relationships with a major party. Many also benefited from being part of rare, strong third-party forces, such as the Farmer-Labor Party, the Progressive Party, and the Nonpartisan League.

The history of independent and third-party Senate bids

On Feb. 15, Kansas City lawyer Craig O’Dear officially announced his candidacy for Missouri’s U.S. Senate seat, currently held by Sen. Claire McCaskill (D). Running as an independent, O’Dear’s 2018 hopes rest on winning a plurality against McCaskill and the likely GOP nominee, state Attorney General Josh Hawley. In fact, the Kansas City Star reported that O’Dear “thinks he can win if he captures 35% to 40% of the vote in a three-way race.” The Crystal Ball will be blunt: Accomplishing such a feat will be extremely difficult for the independent O’Dear, if the historical struggle of independent and third-party candidates is any indication.

Out of nearly 1,900 popular elections for the U.S. Senate since 1913, independent and minor-party candidates have won only 18 times.[1] Of those 18 wins, 16 occurred in regular November elections while two were irregularly-timed special elections. Depending on how one counts or discounts write-in candidates with small vote totals, between 1,100 and 1,200 Senate races have featured at least one independent or minor-party candidate. In just 25 of those elections did such candidates achieve O’Dear’s minimum goal of winning at least 35%.

However, an additional challenge for O’Dear is that he will face both a Democrat and a Republican in the general election. When we exclude the 54 races where one major party failed to field a candidate while a named independent or third-party candidate was winning at least a few votes, the number of times a non-major party candidate won 35% or more shrinks to just 14 elections (11 of which resulted in victory for the independent or minor-party candidate). Table 1 lists the 11 candidates who accomplished this feat in 14 elections; three senators — Sens. Magnus Johnson (FL-MN), Robert La Follette Jr. (Prog.-WI), and Henrik Shipstead (FL-MN) — won at least that share twice.

Table 1: Independent and third-party U.S. Senate candidates who won at least 35% in an election while opposed by both a Democrat and a Republican

Notes: *Special election held on July 16, 1923. “(i)” denotes an incumbent.

Of the 14 elections where an independent or minor-party candidate won 35% or more against both a Democrat and a Republican, incumbents accomplished the feat in eight cases. Eight of the 11 candidates in these 14 elections also had a prior electoral connection to a major party. In recent times, Sens. Joe Lieberman (D-CT) and Lisa Murkowski (R-AK) won general elections after losing renomination in their party primaries, with Lieberman capturing 49.7% as an independent in 2006 and Murkowski remarkably winning 39.5% as a write-in candidate in 2010. In 1970, Sen. Harry Byrd Jr. opted to run for reelection as an independent, leaving the Democratic Party to avoid taking an oath to support its 1972 presidential nominee (although Byrd also might have lost renomination had he run in the Democratic primary). Byrd won a majority, finishing well ahead of the liberal Democratic nominee and a minor GOP candidate. He won reelection in 1976, but the GOP did not contest the race so it is not included.

The other candidates who had previously sought office as a member of a major party largely predated World War II. Shipstead, who won a Senate seat in 1922 as the Farmer-Labor nominee in Minnesota, had previously attempted to win the GOP nomination for a U.S. House seat in 1918 and for governor in 1920, losing both times. He went on to win reelection to the Senate two more times under the Farmer-Labor banner in 1928 and 1934, facing both major parties in the latter contest. In 1940, Shipstead ran and won as a Republican but then lost renomination in the 1946 GOP primary, ending his Senate career. In Wisconsin, Robert La Follette Jr. originally won his Senate seat as a Republican in 1925 (to replace his deceased father, Robert Sr.), but he and his brother, Philip, founded the Wisconsin Progressive Party in 1934 and “Young Bob” won reelection in 1934 and 1940 as the party’s Senate nominee. Later the party folded and La Follette ran again in 1946 as a Republican, losing in the party primary to future infamous red-baiter Sen. Joseph McCarthy. A progressive La Follette contemporary, Sen. George Norris of Nebraska, won election to the Senate four times as a Republican before leaving the party and running as an independent in 1936. He won that race with 43.8%, but lost reelection in 1942 with 28.6% of the vote, short of the 35% mark.

Two others came from North Dakota. William Langer won the GOP nomination for governor in North Dakota in 1932 and went on to win the general election. However, the state supreme court controversially removed him from office in 1934. Langer ran for governor again in 1936, where he narrowly lost the GOP nomination but won the general election as an independent. In 1938, Langer launched a Senate bid, but lost the Republican primary to incumbent Sen. Gerald Nye (R). Langer attempted to win the general election as an independent, but fell short to Nye when bipartisan anti-Langer forces purportedly agreed to support a Democrat in the gubernatorial race and to help Nye in the Senate race. In 1940, Langer defeated incumbent Sen. Lynn Frazier (R) in the Republican primary and then defeated Rep. William Lemke in the general election. Lemke was a GOP congressman who won renomination for his House seat, but he dropped out of his race for reelection and instead opted to mount an unsuccessful independent Senate run against Langer (though his name ran beside the description “Progressive Republican for clean government” on the ballot). Lemke, who won 35.1% in the 1940 Senate race, is perhaps best known as the 1936 presidential nominee of crypto-fascist radio preacher Charles Coughlin’s Union Party. Lemke rounds out the eight candidates who had previously sought office with the major parties but won at least 35% as an independent or third-party candidate in the general election.

Of the three other independent and minor-party candidates who won 35% or more but had not previously sought office with the major parties, two did have ties to the Democrats or Republicans at some point. Sen. James Buckley (C-NY) — brother of noted conservative thought leader William Buckley Jr. — won as the Conservative Party’s nominee in a three-way New York race in 1970. His 38.8% vote share in that contest is the lowest percentage for a winning independent or third-party Senate candidate. Prior to his first run for the Senate in 1968 as the Conservative nominee, Buckley had been a registered Republican. He returned to the Republican fold in 1976, earning the GOP nomination in his failed reelection bid. Four years later, Connecticut Republicans nominated Buckley for U.S. Senate, but he lost the general election. Current Sen. Angus King (I-ME) at one time worked for Sen. William Hathaway (D-ME), but ran for governor in 1994 as an independent, winning that race and reelection in 1998 prior to winning a Senate seat in 2012. He caucuses with the Democrats and is running for reelection this year.

The remaining unmentioned candidate to win at least 35% is Sen. Magnus Johnson (FL-MN). He does not appear to have run for office as a Republican or Democrat, though Minnesota’s state legislature was nonpartisan until the mid-1970s and Johnson served in it. He lost a gubernatorial bid as the Farmer-Labor nominee in 1922 but won a special election in 1923 to take a seat in the U.S. Senate. In that contest, Johnson won 57.5%, the largest share of the vote an independent or minor-party candidate has garnered in a Senate election that also featured a Democrat and a Republican. Nevertheless, Johnson’s success was relatively short-lived as he controversially lost reelection in the 1924 general election by one percentage point. Johnson later returned to Congress as a House member for one term.

Generally speaking, successful Senate candidates who did not have the Democratic or Republican nominations were of two types: Either they belonged to an influential third-party organization in their state or they had previously won as a major-party nominee.

Six of the 11 candidates who won at least 35% belonged to notable third parties. Most of these were at least partly the products of relatively successful third-party movements in the upper Midwest. Johnson and Shipstead won as Minnesota Farmer-Labor candidates, La Follette Jr. won running under his Progressive Party’s banner, and Langer and Lemke won some elections with the backing of the Nonpartisan League in North Dakota. The agrarian NPL heavily influenced North Dakota’s party system prior to World War II, which sometimes created intraparty conflict, particularly in the state’s more dominant Republican Party. While Farmer-Labor, the NPL, and the Progressives affected politics elsewhere, their presence was most heavily felt in Minnesota, North Dakota, and Wisconsin, respectively. In fact, the modern Democratic parties in both Minnesota and North Dakota incorporate these earlier third-party movements: Minnesota has the Democratic-Farmer-Labor Party and North Dakota has the Democratic-Nonpartisan League Party. On top of these Midwestern candidates, James Buckley also belonged to a notable third party, the Conservative Party of New York, which remains an influencer today.

Another four candidates won after having been major-party nominees. Lieberman and Murkowski lost their primaries but still managed to win reelection without their parties’ nominations. Byrd and Norris left their parties and won reelection as independents in the general. Alone among these 11 is King, who was not a member of a third party or elected as a major-party nominee to the Senate prior to winning an election for the upper chamber.

O’Dear is right that he likely needs to win at least 35% to have a chance at victory. Only once has any candidate in U.S. Senate history won an election while winning a smaller share of the vote. In 1914, James Phelan (D) won a Senate race in California with just 31.6%, finishing just ahead of Francis Heney (Prog.) at 28.8% and Joseph Knowland (R) at 28.7%.[2] But the history of independent and minor-party candidates bodes poorly for O’Dear’s chances in 2018. Missouri has also been rather unfriendly to candidates not running as Democrats or Republicans: As Smart Politics pointed out on Tuesday, the best showing for a third-party candidate is 6.1%, which Libertarian Jonathan Dine won in the Show Me State’s 2012 Senate contest. Dine garnered support from some Republicans who did not want to vote for controversial nominee Todd Akin (R) or McCaskill, the Democrat. Unless Hawley or McCaskill make a dramatic mistake between now and Election Day, a mid-single-digit percentage may be the best O’Dear can hope for in 2018.


1. Independent and third-party data in this piece include Sens. Joe Lieberman (D-CT) and Lisa Murkowski (R-AK) — Lieberman lost renomination in Connecticut’s 2006 Democratic primary but successfully ran as an independent in the general election while Murkowski lost renomination in Alaska’s 2010 Republican primary but managed to win as a write-in candidate. Sen. Bernie Sanders’ (I-VT) two Senate wins are also included, though one could make a case that he effectively was the Vermont Democratic Party’s nominee in 2006 and 2012. Democratic primary voters backed Sanders in both 2006 and 2012, but Sanders declined the party’s nomination each time. However, the data do not include any election where the same major party fielded more than one candidate (unless it featured a write-in candidate who identified with a major party, such as Murkowski’s election). It also does not include Sen. Gerald Nye’s (R-ND) win in a June 1926 special election where two different factions of the GOP nominated separate candidates. Nye is sometimes denoted as the Nonpartisan League’s nominee versus Louis Hanna as the “real” Republican, but an agreement was reached whereby neither candidate ran with a party designation in the special election. Hanna and Nye were concurrently running for the GOP nomination for the regular general election in November 1926, which Nye won.

2. This is true while excluding blanket or all-party elections, which this piece does as noted in Footnote 1. However, as Smart Politics notes, Sens. Pappy O’Daniel (D-TX) and John Stennis (D-MS) entered the Senate by winning pluralities in all-party special elections in their home states. O’Daniel won 30.5% in 1941 — narrowly edging out then-Rep. Lyndon B. Johnson (D-TX) — and Stennis won 26.9% in 1947. Both Mississippi and Texas later implemented runoffs for their all-party special election formats.