It could well be the other way around. Progressive activists hate the hard-hitting 'dirtbag' left, they see it as a dangerous threat to their own worldview.
BTW, discussed at https://news.ycombinator.com/item?id=23679425
BTW, discussed at https://news.ycombinator.com/item?id=23679425
Some argue they were a big part of the reason why Bernie's campaign was unable to find much traction outside his core. Of course they blame it on others, even calling other progressives, like Elizabeth Warren, traitors.
I understand these two impulses are probably in direct opposition. I can't want both but I also fear what will happen if we lose a chunk of an entire generation to the far right.
But I wish it could be reclaimed to mean "willing to compromise to move forward" and "doesn't regard anyone who disagrees with him as either a crook or an imbecile".