John this issue has me plenty worried too! I appreciate you parsing the options so clearly. In my dream world, he simply declares he will focus on leading the nation through turbulent times, and let a new candidate become the fresh face of change.

However, looking to past presidents, a leader has to screw up pretty badly to lose an election - either that, or an economic crisis pulled him down - like Carter and Bush Sr.

We might well face such a situation, depending on Covid, Russia, and inflation. These are hard to figure. So I don’t think it’s possible to predict with certainty what would be the best course for Democrats or Biden.