If Biden Drops Out, How Long Do Democrats Have to Pick a Nominee?

If President Biden were to decide to end his re-election campaign, the Democratic Party would technically have until its convention the week of Aug. 19 to nominate a different standard-bearer. But for practical purposes, the deadline would be about two weeks earlier.

That is because Ohio requires candidates to be legally certified by Aug. 7 in order to be included on the state’s ballot. That problem has been on Democrats’ radar for months — it has been an issue, even for Mr. Biden — and the Democratic National Committee has said it will take a virtual roll-call vote before the convention in order to meet the deadline.

Ohio is not expected to be competitive in November; it voted for former President Donald J. Trump by about eight percentage points in both 2016 and 2020. But having no presidential candidate on the ballot would probably depress turnout crucial for down-ballot Democrats like Senator Sherrod Brown.

Earlier this year, there was concern that a similar problem might arise in Alabama. But legislators there ended up passing a bill that postponed the state’s deadline to accommodate the timing of the Democratic convention. Ohio legislators did not do the same.

If Democrats nominate Mr. Biden in the virtual roll-call vote and then change course later, things would get even more complicated.

In the event that a ticket of Mr. Biden and Vice President Kamala Harris were certified to appear on the state’s ballot and Mr. Biden later withdrew, it wasn’t clear whether Ms. Harris would be able to receive votes for president by virtue of already being on the ballot in the vice-presidential spot. The Ohio secretary of state’s office did not immediately respond to a request for clarity on that point.

The Heritage Foundation, a right-wing think tank, has indicated that it might pursue legal challenges to a substitution.