I think we'll let Dan Rather answer that one! ;-)
I think the guy goes to opposition rallies. I think he wants to be a pain, which is why you go to opposition rallies. I think he he knows the kind of response he will get.
But I just don't think those pictures look enough alike for someone to conclude the union guy and his son are the same person. The guy has been vehemently denying that's his son, and says he doesn't know him at all. That kind of thing is easily established, yet he's making the talk-radio circuit adamant in his denials.
I'm not willing to discount the photo. I think the guy clearly likes to stir things up, and he probably shouldn't take his daughter to an opposition rally, but this is supposed to be a free country, and a civilized one.