While most polls show President Joe Biden lagging behind former President Donald Trump, some Democrats have begun to fear that a third-party candidate could make his race even tougher.

That prospect recently led a former Obama White House figure to warn voters that any candidate other than Biden "can't win" in 2024.

"Worse than a political fiction"

Jim Messina served as White House deputy chief of staff as well as manager for former President Barack Obama's 2012 campaign, and he recently made that case in an op-ed for Politico.

"The idea that a 'unity ticket' featuring a Republican and a Democrat could somehow produce a nominee with 'a clear path to victory' is worse than a political fiction," Messina wrote.

Messina singled out the group No Labels, under whose banner West Virginia Democratic Sen. Joe Manchin has not ruled out running.

Opinion | The idea pushed by No Labels that a “unity ticket” with a Republican and a Democrat could produce a winning nominee is a dangerous lie that would simply serve to put Donald Trump back in the White House, writes former Obama official Jim Messina.https://t.co/XPdmRk90rx

— POLITICO (@politico) December 18, 2023

The former Obama staffer accused No Labels of  "pushing a dangerous lie that would simply serve to put [former President] Trump back in the White House."

Messina recalls failed run by Ross Perot

The Hill noted that Messina pointed to the history of third-party candidates in the United States, with the most successful run coming from billionaire Ross Perot, who secured 20 percent of the vote in 1992.

"Can No Labels twist the data and make an argument that Perot could have won if he had done things differently? Sure!," Messina acknowledged.

"But that’s like saying I could have been the quarterback of the Denver Broncos — technically true, but come on!" he added.

"Sure, nearly half of the electorate thinks a third party is necessary, but No Labels mistakenly assumes this means those voters will actually vote for one," Messina insisted.

Poll shows Biden struggling with young voters

He later went on to contend that a "well-funded third-party candidate would be a disaster for our republic — and risks putting us on a direct path to a dictatorship."

Politico published Messina's op-ed on the same day that a Fox News poll found that voters under 30 are almost as likely to support third-party candidates as they are President Biden.

The survey reported that 41 percent would vote for Trump, 28 percent would vote for Biden, 14 percent for Robert F. Kennedy, seven percent for Jill Stein, and 5 percent for Cornel West.