None of the 2012 Democratic or Republican Primary candidates are supporting the Fair Tax. Here is a clip of Ex-Governor Gary Johnson saying that he will run for the Libertarian nomination. And Fair Tax will be a major part of his campaign.
As THE FairTax candidate, I'd really like to support Gary, but he has some liberal points of view that I find hard to stomach. I think I'd have felt better if he had said that certain issues should be left to the states. Though even then, I'm not sure. I'm still considering writing in Herman Cain even if it doesn't count in the primary.