because his audiences subliminally identify with it, because that's what they are themselves - and they like to project it out on their political leaders instead of honestly acknowledging it in themselves. Heck, Barack Obama is one of the most intelligent, competent and well prepared for his job presidents we have had in a long time, but these @$$holes project their own racism and stupidity out onto him, by obstructing everything Obama tries to do, and then framing him to make him look stupid or incompetent.
One really scary thing that I saw in a recent video posted on DU - whose title went something like "Oops - fascism!" was Donald getting his audience to give the old Nazi arm salute to him and pledge their allegiance to him at a recent rally. Did anyone here see that video? Boy, was that ever scary! The Donald was administering a stupid test to his audience, and they were qualifying with flying colors! These idiots and imbeciles were so dumbed down, so ignorant of even the basics of recent history that that went completely under their radar. That is not only really stupid, but really scary!