Joe Biden withdraws from race Sunday, 107 days before Election Day. What happens next?

President Joe Biden, 81, announced Sunday he is dropping out of the 2024 presidential election, ending the prospect of a rematch against former president Donald Trump .

Questions about Biden's fitness for a second term as the oldest sitting president took on new significance earlier this year when a special counsel report called him an " elderly man with a poor memory. " Those questions dominated the political discourse after his d isastrous debate against Trump on June 27 .

Since then, more than 35 lawmakers have called on Biden to step aside.

Now the party must find a new champion to rally behind with a little more than 100 days until Election Day. Here is what could be coming next:

More: If President Joe Biden steps down, is America ready for President Kamala Harris?

Did Joe Biden drop out of the presidential race?

Biden has announced he's withdrawn from the 2024 election.

Top of mind for Democrats is who to put forward as a new presidential candidate.

Vice President Kamala Harris , 59, is the most logical replacement, and Biden in making his decision to drop out of the race also endorsed her. Many Democrats have resisted rallying behind Harris as the alternative.

These other leaders have been commonly named as other possible replacements:

• Michigan Gov. Gretchen Whitmer
• California Gov. Gavin Newsom
• Illinois Gov. J.B. Pritzker
• Pennsylvania Gov. Josh Shapiro
• Kentucky Gov. Andy Beshear

Look back: Who ran for president in 2020? An interactive guide

All eyes on Democratic National Committee to nominate new candidate

Although the Democratic National Convention is scheduled for Aug 19., it still remains to be seen how the nomination will happen.

The nomination date has already been a pain point for the party.

While the roll-call process of delegates formally casting their votes typically happens at the convention, the DNC Convention Rules Committee has been trying to hold a virtual nomination ahead of the convention. This push came after a legal challenge from a Republican Secretary of State in Ohio threatened to keep Biden off the ballot because of electoral deadlines in the state . The committee co-chairs say similar challenges may arise in several other states.

When exactly this roll-call vote will occur has been a moving target, especially once the movement to replace Biden on the ticket began gathering momentum.

If the virtual nomination does not happen, Democrats could be looking at an open convention in August.

If no nomination, open convention decides party candidate

The convention, scheduled for Aug. 19-22, is taking place in Chicago , where the party also held a disastrous convention in 1968 after incumbent President Lyndon B. Johnson opted to not seek reelection earlier in the year. Amid anti-war protests and a divided Democratic party, the convention is thought to have significantly damaged the party's campaign that year.

That year was also the last time the Democratic Party had an open convention. Unlike most modern conventions where delegates cast votes for the presumed nominee based on their state contests, open conventions happen without a presumed nominee. That means the party representatives from across the country would be able to cast their votes for whoever emerged to nominate a presidential candidate.

What about all the campaign money?

As Biden has been running for reelection since April 2023 , he has raised hundreds of millions of dollars in campaign funds. That money is spread across a few fundraising committees.

Harris could inherit a substantial amount of that as her name is on campaign documents, but this unprecedented change has yet to be tested against campaign finance laws.

The DNC also has a substantial campaign war chest, and they could likely use that money for whoever the nominee is.

The joint fundraising committees and the super PACs funding Biden's campaigns would have handle changes in where their donations are allocated within their organizations.

Contributing: Sam Woodward, Erin Mansfield, Phillip M. Bailey, Nick Penzenstadler, Francesca Chambers, Deborah Barfield Berry , Joey Garrison , Michael Collins, David Jackson, Michael Loria

This article originally appeared on USA TODAY: Joe Biden withdraws from race Sunday, 107 days before Election Day. What happens next?