By Anthony Zurcher
US senator Joe Manchin, a self-described 'conservative Democrat' has criticised both major parties and their leaders in recent years. Photo: Samuel Corum / GETTY IMAGES NORTH AMERICA / Getty Images via AFP
When Joe Manchin, one of the most high-profile centrists in US politics, announced he would not be running for president on Friday, you could almost hear the sigh of relief from the Biden campaign.
The West Virginia senator had said he was considering a run to provide an alternative to voters unhappy with both Joe Biden and Donald Trump.
The self-described "conservative Democrat" has criticised both major parties and their leaders in recent years.
Democrats were concerned that an independent bid could help deliver the White House to the Republicans in November's election.
Manchin finally ended the speculation on Friday, and seemed to acknowledge that the prospect of such unintended consequences was a factor in his decision not to run.
"I will not be a deal-breaker or a spoiler," he said in a speech in his home state.
News of Manchin's decision will be well received in the White House.
"Democrats have been really freaking out at the prospect of a third party candidate, especially one who comes from a more moderate, centrist background," says Amy Walters, editor of the Cook Political Report, which analyses campaigns and elections.
Polls suggest that there is fertile ground this year for an independent or third-party campaign, given that a majority of Americans have expressed dissatisfaction with a Biden-Trump rematch of the 2020 campaign.
"Those swing voters who are not going to back Trump could defect to another candidate," Walters added.
Manchin may not have been best situated to take advantage of these political conditions, however.
At 76, the senator is close to the same age as his two major-party rivals, so he could not provide a youthful contrast. And while Manchin's brand of political moderation - with a focus on budgetary restraint - may have peeled off some Democrats and Republicans, in the current climate of political polarisation that appeal may have had its limitations.
After word of Manchin's decision spread, the centrist group No Labels - which is contemplating fielding a presidential candidate and was reportedly considering Manchin for the task - released a statement saying its work would continue.
"No Labels is currently speaking with several exceptional leaders about serving on the presidential unity ticket," the group posted on social media. "We are continuing to make great progress on our ballot access efforts and will announce in the coming weeks whether we will offer our line to a unity ticket."
Former Maryland Governor Larry Hogan, who was reportedly considered by No Labels, announced earlier this week that he would run for his state's open Senate seat as a Republican - effectively removing his name from consideration.
In what is shaping up to be a close race between Biden and Trump, small changes in the preferences of voters could have a significant impact in how the presidency is ultimately decided. In 2020, for example, Biden won three key states - Pennsylvania, Georgia and Wisconsin - by just a combined 44,000 votes.
With several independent candidates already running, including Robert Kennedy Jr and the academic Cornel West, an electoral wild card could still shake up what has been a relatively stable 2024 campaign so far.
- This story was first published by BBC