I likely come from a different political perspective than Winetarelli, but I agree with the points he made. I believe the progressive, far left part of the Democratic party has taken over, at least from a news and policy point of view. They are the most vocal and it seems that many of the candidates are bending over to the left as far as they can to kowtow to this group. I am not sure they represent the entirety of the Democratic party. The candidates may get pulled over to the left so far that the winner may have trouble getting acceptance from the middle of the party and independents.
I am also concerned about the loss of voices from the liberal part of Democrats and many of the far left illiberal are controlling speech. Liberals are supposed to support free speech and be willing to discuss issues from people with other perspectives. Right now I see the far left shutting down any discussions and attacking others with racism, mysogeny or other terms to avoid dealing with ideas from the other side. This goes to what is happening on campuses with some of the students shutting down speech and requiring safe spaces. The university is supposed to be a place of free discussion and learning about other perspectives.
I am not saying that there aren't problems on the right, or that Trump is always right. I think he is an egotistical jerk who doesn't manage his message well at all. But the liberal portion of the left needs to take better control of the party and get back to rational discussions and promoting ideas that are more representative of their base.