Biden skeptics say he would meet the same fate as Hillary Clinton and John Kerry, campaigning as a longtime creature of Washington who appears to have “electability” but lacks a fresh vision. They believe his long record allows Trump to replay his 2016 strategy in industrial states that decided the election — undermine Biden with the middle class by highlighting his support for unpopular trade deals like NAFTA, and use his spotty record on race to tamp down the enthusiasm of minority voters.

“I believe Joe Biden is more of a gamble than anyone in the political establishment is willing to say out loud,” said Rebecca Katz, a progressive strategist and former aide to Senator Harry Reid of Nevada and New York City Mayor Bill de Blasio, who is also running for president.

“It’s not just Hillary Clinton. Look at John Kerry before her. Look at Al Gore. Democrats keep nominating candidates who they think are the best-qualified to win, but the candidates who actually win are the ones that people did not predict,” Katz said, citing Barack Obama. “At what point do the smart D.C. insiders stop pretending they know what electability really means and start asking the question: Who are the voters most passionate about?”

Biden’s campaign said those comparisons are irrelevant because 2020 is a unique playing field.