What could happen if Biden drops out the race?

The Democratic Party's rules provide a framework for scenarios where Biden might step aside before formal nomination or if a vacancy arises post-nomination.  

In such an unprecedented event, the party might opt to amend its rules regarding candidate replacement.  Furthermore, if this occurs post-convention, state laws could pose challenges in replacing Biden on certain ballots.

Here's an overview of potential outcomes if Biden decides to withdraw from the race: