But then that last sentence is precisely what the people with the banners and the lies and the screaming would no doubt they of themselves say of themselves, and they believe it too.   

The puzzle is where it's coming from, so far as the non-racists among them. I think one part of it is a mindset that says that in a battle the only thing that matters is winning, and anything that helps achieve that is OK. And that's not an attitude restricted to the right.

Why, even Saul Alinsky - whom I admire enormously in many ways - says more or less precisely that in Rules for Radicals. And to me it seems that may be a way to win a battle, but it's also a good way to lose a war in the end.