A broad church with many one-issue voters will always be a fukking disaster, especially when you try to placate one and all equally.
Surely it is not difficult to establish the most important policy achievements to satisfy the rump of your voter base; ensure that these are realistic and deliverable across the duration of a term; campaign and message on those.
Am I missing something?!
The problem is that nothing is really deliverable. Republicans aren't going to let anything past the Senate as long as Dems are in control.
They're just not. The best Dems can do is Executive Orders and those can only go so far.