Meet the spoilers: Who's declared or considering third-party White House bids

• Voters have been uninspired by Biden's and Trump's candidacies, polling has shown. Third-party candidates could capture the large percentage of Americans who are turned off by both.
• Meanwhile, the GOP presidential primary field has been rapidly shrinking, and three other Democratic candidates remain in the race as long-shot alternatives to Biden.

State of play: Three notable candidates have declared bids, while groups including No Labels have been seeking a centrist nominee.

• Former Rep. Liz Cheney (R-Wyo.) said in early December she was considering a third-party presidential bid, seeking to do "whatever it takes" to stop Trump from being elected.
• Former Maryland Gov. Larry Hogan (R), a co-chair of No Labels, may have signaled a third-party presidential bid in an ad from November. In it, he attacked Democrats' and Republicans' foreign policies, specifically progressives for questioning support for Israel and Republicans for opposing funding for Ukraine.
• Democratic Sen. Joe Manchin in February ended months of speculation that he might launch a bid following his announcement he wouldn't run for re-election in West Virginia.

Here's who's launched a third-party campaign so far:

RFK Jr. polls higher than previous independent candidates

• Robert F. Kennedy Jr. dropped his Democratic party bid in October to run as an independent, and he has polled as high as 20% in a hypothetical three-way matchup with Trump and Biden.
• Kennedy spread misinformation about vaccines during the COVID-19 pandemic and, in contrast with Democrats, has criticized U.S. funding for Ukraine. Despite being a scion of America's most storied Democratic dynasty, he has garnered significant conservative support.
• A super PAC backing Kennedy, an environmental lawyer, plans to spend between $10 and $15 million to get him on the ballot in 10 states, the New York Times reported in early December. As of November, he polled higher than any independent or third-party candidate in a generation, CNN reported.

West aims to "break the grip of the duopoly"

• Cornel West, a prominent progressive scholar and activist, is running as an independent after previously registering with the Green and People's parties.

• The "policy pillars" listed on his campaign website include economic, environmental and racial justice.
• West is more likely to appeal to voters who backed Biden over Trump in 2020. A November Quinnipiac poll put him at 3%, tied with Green Party candidate Jill Stein.

Stein runs again after key role in 2016

• Stein, a physician by training, was the Green Party candidate in 2012 and 2016. She had previously backed West to be the Green Party nominee in 2024, but announced her own candidacy on Nov. 9 after he opted to run as an independent.
• Stein received 1% of the vote nationally in 2016, but her share in key swing states was bigger than Trump's margin of victory over Hillary Clinton, leading some to accuse her of tipping the election to Trump. Stein has rejected those claims.
• Stein has accused Biden of "aiding and abetting" Israeli "war crimes" in Gaza. She says she will campaign for a Green New Deal, a proposal to reach net-zero greenhouse gas emissions and 100% renewable energy by 2030.

Go deeper: Meet the 2024 presidential candidates

Editor's note: This story has been updated to reflect additional developments in the 2024 election.