Since Bernie is a self-described socialist, I can’t see why applying that label to him would be offensive or out of bounds. He embraces it.
FWIW I think the board does a fair job of monitoring itself. This issue obviously struck a visceral nerve with a lot of people, myself included. Over the years when I have posted things that go against the popular sentiment, I have felt safe to do so even though the response is predictably negative. If I find myself swimming too hard against the current after three posts, I shut it down and move on.
And as Bob said, PMs that are over the line can be reported.