Nearly two-thirds of Democrats say President Joe Biden should withdraw from the presidential race and let his party select a different candidate, according to a new poll. 

It sharply undercuts his post-debate claim that “average Democrats” are still with him even if some “big names” are turning on him. 

The new survey by AP-NORC was conducted two weeks after Biden’s debate flop. It also found that only about 3 in 10 Democrats are extremely or very confident that Biden has the mental capability to serve as president. That's down from 40% in a poll from February. 

The findings underscore the challenges the 81-year-old president faces as he works to silence calls from within his own party to leave the race. Democrats plan a virtual nominating roll call for early August -- not this month -- giving more time for a possible change in the ticket.

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