Unless they run in the first election as a bridge candidate and then, after being elected, refuse to confirm that he won’t run again for multiple years.

Edit: y’all can rewrite history all you want and insist that the party cannot fail because it can only be failed, but he said what he said: https://www.theguardian.com/us-news/2020/mar/10/joe-biden-michigan-rally-kamala-harris-cory-booker

Hold on, last election he refused to say so explicitly, but he repeatedly implied he wouldn’t run for a second term and described himself as a bridge candidate. Then he demanded a second term at the last minute.