Both conservatives and liberals should call out any groups that are extreme. There is no excuse for not doing so. Why would anyone want their ideology to be warped by some fringe group.
Gawd... Do you really not see what's going on? Trump found fine people walking alongside folks with Nazi flags. There is no equivalent to that on the left. No one on the left wants to have anything to do with antifa, or their ideology, for that matter. All the while, the alt right with Bannon, Miller, Bolton, Pompeo and Trump as spearhead, is taking over the GOP.
That's why the nitwits on the right try to create the appearance of an equivalence. They know they are filthy like swine, and that won't change. So, the only way out is to smear the other side until everyone appears equally filthy, in the hope that no one notices. Wake up already!