I mean there’d be no enforcement mechanism to make President Bernie do M4A, once he’s in office he can do whatever. You could maybe theoretically have an accountable politician in a bourgeois democracy if their entire campaign apparatus was done by a worker’s party, and if they did bad stuff in office the party would guarantee that they would not be reelected. But dubious on a national level or with term limits - think of all the stuff the lame duck presidents do. Right now the social democrats have their own campaigns that get support from a bunch of different orgs, so when DSA helps elect a promising politician they can generally just fuck off, break all their promises to the org, and get reelected on their own as an incumbent.