So only progressives can run in the Democratic party? If so, then there's your problem and why you can't easily stomp Trump in an election.
Funny, they use the word Progressive to describe themselves when, they are really Socialists and Communists. If people knew the truth, they would have even less support? Look at Bernie Sanders, full out Socialist which he does not deny which is a good thing, honesty wise. These extreme liberals also, know, the more people know that they are Socialist or Communist, the less votes they get. That is why Bernie Sanders cannot even put away Sleepy Joe Biden. Biden even half-asleep, beat Bernie Sanders by a mile.