At the gatherings in Bucks and Delaware Counties, outside Philadelphia, there was plenty of support for several candidates. In a straw poll at the Newtown picnic — held with Democratic-approved paper straws, not plastic — the results were: Elizabeth Warren, 15, Kamala Harris, 14, Mr. Biden, 8 and Pete Buttigieg, 7. Bernie Sanders earned just one vote.

[We tracked down the 2020 Democrats and asked them the same set of questions. Watch them answer.]

Julia Woldorf, a member of the Newtown Borough Council, argued that Mr. Biden was a poor choice if voters were trying to be practical about the candidates. She brought up Ms. Harris’s sharp-scalpeled attack on him in the first debate over his civil rights record, which caught Mr. Biden off guard.

“He showed me he couldn’t respond the way he should have,” Ms. Woldorf said. “If Trump throws something at him, how’s he going to respond?”

There were echoes of the hand-wringing among some national Democrats over whether candidates were lurching too far leftward to win with plans that would end private health insurance or decriminalize unauthorized border crossings.

“I think ‘the squad’ is leading us too far to the left, and we’re alienating a lot of folks in the middle,” said Susan Turner, a retired engineer who now owns the Green Frog Bakery in Newtown, referring to the four progressive congresswomen who have clashed with Speaker Nancy Pelosi.

Steve Cickay, a retired I.R.S. executive, played down Democratic fretting over whether Mr. Biden was too old to motivate younger voters.