The debate over Rush Limbaugh's NFL bid is roiling the racial landscape. This evening, after Juan Williams explained that Rush's "Barack the Magic Negro" parody was based on a column by an African-American author, a black radio talk show host told Williams to "go back to the porch." [H/t NB readers Tracy B. and Ken T.] Warren Ballantine uttered the insult on this evening's Countdown. View video here.