“Spoiler” candidates harm Republicans

“Spoiler” candidates harm Republicans in the United States

Many elections in the United States have only two candidates on the ballot, and the winner receives more than half of the votes. However, minor parties and independents can “split” the majority, causing a candidate without majority support to win. Here are recent examples.

Republicans are harder hit than Democrats because Libertarian candidates tend to pull votes from Republicans. Green Party candidates do the same to Democrats, but Libertarians tend to significantly outperform Greens, meaning Republicans pay the price.

Spoilers have caused 15 Democrats to win Senate seats in 25 years

Over 25 years, we estimate Republicans have lost 15 Senate seats to Democrats due to the spoiler effect.

This chart shows key Senate races where Democrats won with less than a majority, and their victory margin was smaller than the votes cast for right-of-center third-party and independent candidates. In a head-to-head race between the winning Democrat and the losing Republican, the Republican candidates likely would have been favored to win; most of these Democrats still serve in the U.S. Senate today.

Year	State	Democratic Winner		Republican Runner-up		Other candidates
1998	Nevada	Harry Reid	47.9%	John Ensign	47.8%	Libertarian	1.9%
2000	Washington	Maria Cantwell	48.7%	Slade Gorton	48.6%	Libertarian	2.6%
2002	South Dakota	Tim Johnson	49.6%	John Thune	49.5%	Write-ins only	0.9%
2006	Montana	Jon Tester	49.2%	Conrad Burns	48.3%	Libertarian	2.6%
2008	Oregon	Jeff Merkley	48.9%	Gordon Smith	45.6%	Constitution	5.2%
2008	Alaska	Mark Begich	47.8%	Ted Stevens	46.5%	AK Independence	5.6%
2012	Montana	Jon Tester	48.6%	Denny Rehberg	48.3%	Libertarian	6.6%
2014	Virginia	Mark Warner	49.1%	Ed Gillespie	48.3%	Libertarian	2.4%
2016	Nevada	Catherine Cortez Masto	47.1%	Joe Heck	44.5%	None of the above / Indep. American	5.3%
2016	New Hampshire	Maggie Hassan	48.0%	Kelly Ayotte	47.9%	Libertarian & Independent	4.2%
2018	West Virginia	Joe Manchin	49.6%	Patrick Morrisey	46.3%	Libertarian	4.2%
2022	Nevada	Catherine Cortez Masto	48.8%	Adam Laxalt	48.0%	None of the above	1.2%
2024	Nevada	Jacky Rosen	47.8%	Sam Brown	46.2%	Libertarian & Indep. American	3.8%
2024	Michigan	Elissa Slotkin	48.6%	Mike Rogers	48.3%	Libertarian	1.0%
2024	Wisconsin	Tammy Baldwin	49.4%	Eric Hovde	48.5%	Indep. & America First	2.1%

Republicans also sometimes win Senate races by a plurality of the vote. However, it has often been in spite of right-of-center candidates splitting the majority.

Spoilers impacting the presidency

In 2020, the presidential election came down to close elections where Joe Biden won with less than 50% in Arizona, Georgia and Wisconsin — where a shift of just 23,000 votes would likely have elected Donald Trump instead. In each of those states, the only third party candidate on the presidential ballot was Jo Jorgensen of the Libertarian Party. The votes for Jorgensen were greater than the margin between Biden and Trump, meaning Jorgensen may have played “spoiler” and harmed Trump’s chances in those states. Here are the results:

Arizona: Biden wins by 0.3% and Jo Jorgensen earns 1.5%
Georgia: Biden wins by 0.23% and Jo Jorgensen wins 1.24%
Wisconsin: Biden wins by 0.63%, and Jo Jorgesen wins 1.17%

This would not be the first time a presidential election was affected by plurality voting rules. In 1992, for example, Ross Perot won 18.9% of the vote, while Bill Clinton defeated George Herbert Walker Bush by 43% to 37.5% Clinton carried only a single state with over 50% and won by a plurality in such states as Georgia and Montana.

While the spoiler effect did not appear to cost Donald Trump any states in 2024, Republicans remain vulnerable in future campaigns due to the stronger performance of Libertarians and other right-of-center groups, relative to parties that could play spoiler to Democrats.