An NPR/PBS NewsHour/Marist poll released Monday found that 41 percent of Democrats believed that Biden was the best Democratic candidate for the next election, while 41 percent preferred “someone else.” Another 18 percent were undecided. Democratic-leaning independent voters had less confidence in the president’s prospects for re-election, with 51 percent saying that a different Democrat would stand a better chance.

When poll results from both Democrats and Democratic-leaning independents were combined, a 44 percent plurality preferred a different candidate, while 36 percent said that Biden was the best choice. In the South and Midwest, 51 percent preferred a different candidate. The president had the most support in the West, where a plurality of 45 percent preferred Biden.

Republicans and Republican-leaning independents were somewhat more confident that former President Donald Trump was the best candidate for 2024. Half preferred Trump, while 35 percent favored a different candidate and 14 percent were undecided. Trump’s strongest support was among Republicans, with 57 percent supporting the ex-president. A 47 percent plurality of Republican-leaning independents were in favor of a different candidate.

The poll suggested that a majority of Republicans are likely to refuse to accept election results if their candidate does not win, with 59 percent saying that they would not “trust that the results are accurate” if their 2024 choice for president is not declared the winner. Only 13 percent of Democrats and 26 percent of independent voters said the same.

The poll was conducted nationally among 1,209 adults over the phone from October 18 to October 22. It has an overall margin of error of 4 percent, with a 6.4 percent margin of error for the Democrats and Democratic-leaning independents subset and a 6.8 percent margin of error for the Republicans and Republican-leaning independents subset.

It is not entirely clear that Biden will run for re-election in 2024. Although the president has said that he expects to run, he has not fully committed. Questions about Biden’s re-election prospects were raised even before he won the presidency in 2020, mostly due to his advanced age. At 78 years old, Biden is already the oldest sitting U.S. president ever and will be 81 at the time of the 2024 election.

If Biden does run, a 2020 election rematch is a possibility but also uncertain. Trump, who will be 78 years old at the time of the next election, has repeatedly hinted that he intendeds to seek a non-consecutive second term while stopping short of making a firm commitment.

Newsweek reached out to the White House for comment.