If we can move away from insane pseudo-political ranting and homophobic panic for just a moment: I think the reasoning behind the clothes politicians wear is the same as the reasoning behind the things politicians say: they eliminate everything that can be spun negatively by their opponents, and what's left is what they wear. Of course it has to be a certain amount of "dressy," or they'll be perceived as unserious, but it can't be too flashy, or they'll be portrayed as out of touch with the common man, or worse, fruity. (Apparently getting away from homophobic panic isn't as easy as I thought.) Everything politicians do (and, increasingly, everything period) comes down to controlling spin.
That was an excellent point several posts back about the red, white, and blue thing. It's a testament to the powerful subliminal effect of that tactic that, even having noticed for over a year that the basic Obama uniform consists of blue suit white shirt red tie, almost always, I never actually made the connection to the flag. But I did vote for him, so, there you have it, I guess!