Frank Rich of the NYT has a piece (actually two pieces) about where all the tea party rage comes from. A main theme of the, as usual, very well done articles is that the tea party is upset that blacks, gays, Hispanics, and Jews are in the ascendency in various higher-level Government jobs. Point made.
As a kid from Cincinnati, I'll put it in more simple terms. The Limbaughs, Becks, Palins, are providing oh-so-veiled language (less veiled in Limbaugh's case) which can be used to decry the fact that we have a N...r in the white house. Period.