Can Joe Biden be replaced?

President Joe Biden’s uneven performance against Donald Trump in the first presidential debate Thursday night has raised concerns for some about his ability to serve a second term in office. 

It’s even leading to questions of whether Biden should consider stepping aside as the Democratic nominee for president, even among members of his own party, out of fear that Trump could become president again. 

The 81-year-old was occasionally shaky during the debate, which led to people on social media offering their commentary. A person close to the situation told the Associated Press that the president was dealing with a cold during the debate, sharing that he tested negative for COVID-19. 

RELATED: Biden's voice raises questions among viewers during debate

Biden also appeared to struggle to gather his thoughts at times, faltering as he answered questions on tax policy, health care, and abortion rights. 

FILE-President Joe Biden delivers remarks during the CNN Presidential Debate at the CNN Studios on June 27, 2024 in Atlanta, Georgia. (Photo by Justin Sullivan/Getty Images)

The president didn’t talk about his performance at Thursday night’s debate, with the AP noting that the president has no intention of leaving the presidential race.

It would be nearly impossible for Democrats to replace Biden based on several factors. 

Delegates bound to Biden

Every state has already held its presidential primary. Democratic rules mandate that the delegates Biden won remain bound to support him at the party's upcoming national convention unless he tells them he’s leaving the race, according to the AP. 

The conventions and their rules are controlled by the political parties. The Democratic National Committee could meet before the convention opens on Aug. 19 and change how things will work, but that isn't likely as long as Biden wants to continue seeking reelection.

Could Kamala Harris replace Biden?

Vice President Kamala Harris is Biden's running mate, but that doesn't mean she can swap in for him at the top of the ticket by default. Biden also can't decree that she replace him should he suddenly decide to leave the race.

If Biden chooses to abandon his reelection campaign, Harris would join other top Democratic candidates looking to replace him. But that would create a scenario where she and others end up lobbying individual state delegations at the convention for their support, the AP reported. 

What about other potential Democratic candidates?

In addition to Harris, others that endorsed Biden in 2024 while having their own presidential aspirations for future election cycles include California Gov. Gavin Newsom, Michigan Gov. Gretchen Whitmer, Pennsylvania Gov. Josh Shapiro, Illinois Gov. J. B. Pritzker and California Rep. Ro Khanna.

Moreover, other candidates who Biden defeated during the party’s 2020 presidential primary could  try again, including Sens. Bernie Sanders of Vermont, Elizabeth Warren of Massachusetts and Amy Klobuchar of Minnesota, as well as Transportation Secretary Pete Buttigieg.

RELATED: Here's who won the presidential debate, according to polls

Citing a recent Gallup Poll from before the debate, the Associated Press noted that 59% of people said they were "very concerned" that Biden is too old to be president compared to 18% who were worried about Trump’s age. That same poll found that Biden’s age was very concerning among 31% of Democrats. 

The Associated Press contributed to this report.  This story was reported from Washington, D.C.