I wouldn't say there was or is silence. Go to ZNet and you'll find plenty of denunciations of Saddam, for instance.
I've cruised some of the Leftier Than Thou lists, and there are arcane discussions about Saddam being anti-hegemonic, objectively anti-imperialist in this specific instance, and so on; but even there, I don't see much in the way of Ba'athist endorsement, despite some of the ridiculous assertions.
DP