I wouldn't call either Eric Alterman or Max Blumenthal "radical leftist." Alterman is left-liberal and Blumenthal is left. The terms a**hole and d-bag apply to Alterman and certainly to the tweeter. Just look at his face.
7 November 2013 update: Takes one to know one.
Dear Mondoweiss dipshits. Phil Weiss has repeatedly tried to get me to debate him and I always say "no" because it would be a waste of time— Eric Alterman (@Eric_Alterman) November 8, 2013