Supporting the Democratic nominee, no matter who it may be.
Everything else is just noise.
Vote how you want during the primary. If your preferred candidate wins, great! If your preferred candidate loses, that’s too bad. The primary is a zero-sum game.
So is the general. Once we have a nominee, set aside your differences, throw what weight you can muster behind that nominee, and, fer crissakes, VOTE for the nominee!
It’s the absolute least you can do while still being productive. Anything less and you’re an obstacle.