WASHINGTON — Nearly twothirds of Democrats say President Joe Biden should withdraw from the presidential race and let his party nominate a different candidate, according to a new poll, sharply undercutting his post-debate claim that “average Democrats” are still with him even if some “big names” are turning on him.

The new survey by the AP-NORC Center for Public Affairs Research also found that only about 3 in 10 Democrats are extremely or very confident that he has the mental capability to serve effectively as president.

The findings underscore the challenges the 81-year-old president faces as he tries to silence calls from within his own party to leave the race.

The poll was conducted mostly before Saturday’s assassination attempt on Trump at a campaign rally in Pennsylvania. It’s unclear whether the shooting influenced people’s views of Biden, but the small number of poll interviews completed after the shooting provided no early indication that his prospects improved.

Meanwhile, as Vice President Kamala Harris receives additional scrutiny amid the talk about whether Biden should bow out, the poll found that her favorability rating is similar to his — but the share of Americans who have an unfavorable opinion of her is slightly lower.

Most Democrats — around 6 in 10 — say that Vice President Harris would make a good president, while 22 percent think not and 2 in 10 don’t know enough to say.

Only about a third of Democrats believe Biden is more capable of winning the November election than is Trump.

The poll of 1,253 adults was conducted July 11-15, 2024, using a sample drawn from NORC’s probability-based AmeriSpeak Panel, which is designed to be representative of the U.S. population

.The margin of sampling error for all respondents is plus or minus 3.8 percentage points.