The former Democrat, who unsuccessfully led an effort to oust President Jimmy Carter from the 1980 Democratic convention, said he expects Biden will likely step down before next month's Democratic National Convention in Chicago.
Former Rep. Mike Burns (D-Md.) told the New York Post that Biden could leave office within days.
“I don't think the way things are going right now it's going to go to the Democratic National Convention,” he told The Washington Post in an interview on Friday. “I think Biden will probably walk out within the next few days.”
At the 1980 Democratic Convention, held at Madison Square Garden in New York, Carter defeated a challenge from Ted Kennedy, the Democratic senator from Massachusetts.
Biden has resisted calls to drop out of the presidential race after being heavily criticized for his performance in last month's debate and is persisting as the Democratic nominee.
“If he goes to the convention seeking the nomination and gets all his forces working with the delegates, I think he'll get the nomination,” Burns said.
Delegates are expected to nominate Biden and Vice President Kamala Harris in a virtual roll call before Ohio's votes close on August 7.
Burns said concerns about Biden's age are well-founded.
“I'm 80 years old and I'm in pretty good shape. I swam a mile yesterday and played golf the day before. I'm going to the gym later today for an hour and a half.
“But to think about running for president of the United States and serving as president from now until January 20, 2029, to me, is insanity,” he added. “So yeah, this is insanity.”