I think left-wing veterans fill the same role as black republicans. In both cases, political activists can display them as if to say, "See, he's one of them and he agrees with our politics."
So're we, when it comes to it. Or we would be if conservatives ever held us up for admiration.
Left-wing veterans are the result of a drill sergeant dropping the person in question on their head in basic training.
Well said Hortensio.