I was under the impression that socialists used to be VERY anti-Communist. Hendryk, who describes himself as a "moderate social democrat," has criticized Communism on the board.
However, there seems to be a lot of Soviet apologia in socialist circles, such as William Blum's Killing Hope, in which he basically endorsed the "revisionist theory" (the US, not the USSR, was responsible for the Cold War) and endorsed the Soviet invasion of Afghanistan to boot.
So how might we make it so socialists remain extremely anti-Communist?
Vietnam might be the big source for PODs, as the "revisionist arguement" gained credibility as a result of the Vietnam War and IIRC it was Vietnam that radicalized Blum.