Now is a great time for if I were there hypotheticals, so here’s mine.
Once it was decided to run Harris and push Biden out, they should have gone all the way and used the 25th amendment to let Harris become president. This would have effectively separated her from Biden while still allowing her to take credit for the good stuff. She could have instructed the DOJ to start investigating price gouging now, and campaigned on needing to win to keep it up.
The 100ish days wouldn’t have been enough for wholesale replacement, but it could have created a concrete message of this is where I want to go. A campaign focused on already delivering is a positive message people could get behind as well.
Except… they won’t, though neither will the conservatives. The only thing required for evil to flourish is for good people to do nothing. Which there seem not enough of, at least in comparison to the forces on the other side that want to tear everything down - in fairness, it is significantly easier (and thus needs far fewer resources) to destroy than to create.