As the Democratic candidate for the upcoming general election, Joe Biden is unlikely to step down or become physically unable to run for president. In fact, he has built up significant support for his campaign and it’s difficult to envision a viable candidate other than him at this time.
If Biden were to step down, Democrats would face a challenge in choosing a new candidate. While waiting for the results of the primaries, his announcement would need to wait until after they end on June 4. If he were to retire, there would be a new battle for his replacement among potential successors such as Kamala Harris, governors Gavin Newsom and JB Pritzker and others.
However, if Biden were to leave the race at a late date, Democrats would be faced with serious logistical challenges as early voting has already begun in some states. Both parties are facing similar challenges as Donald Trump, the likely Republican candidate, is also approaching election age limitations and has faced legal issues that could affect his eligibility to run for president. Ultimately, due to weakened national parties, there are few candidates of stature who could easily replace either Biden or Trump. Both parties have few mechanisms to sway their candidates from continuing their campaigns.