Listen, Dems. Progressive messages work better in some places and moderate messages work better in others. In some places they work equally well, each message attracting and repelling different but equivalent sets of voters. Don't make it harder than it needs to be.
I understand that the establishment/moderate complaint is that since moderates would also win "safe" districts where progressives thrive, progressive electeds in those districts should shut up, lay low, and stop having such a huge national profile. But that's just dumb.
It's a big coalition, and there's going to be ideological and strategic disagreement. Trying to mute the party's rising and most energized faction predictably inspires insurrection and does far more to divide than unify.
Moderates can't act like they're entitled to the brand. They have to work for it, build institutions, organizational infrastructure and an appealing, distinctive national profile of their own other than "Republican Lite" or progressives, who are better at all this, will win.