The Republicans really, really don't like Mitt Romney. The tea party Republicans positively despise him.
If the tea partiers had a single candidate, they could swamp Romney and chase him out of the race, but they don't. They are fragmented, squabbling among themselves over which candidate offers them a chance to win. So far they have tried out Michele Bachmann, Rick Perry, Herman Cain, Newt Gingrich, and Rick Santorum, but they haven't fallen in love with any of them - at least not for more than a few weeks. Meantime, the inevitable Mitt Romney rolls on and looks to be unstoppable. Will they finally, grudgingly, get behind Mitt?
Well, if there is one man they despise more than Mitt, it is Barack Obama. For these people, he will always be the illegitimate, Kenyan, socialist, Muslim, privileged, elite, black man who usurped the White House. The fact that the truth is that he is none of those things - except a half African-American, half white man which makes him black in the eyes of the world - matters not a whit. When they look at him they see a black face, and nothing else really matters to them. They can't see past the color of his skin to recognize that, in fact, his is a very traditional Republican presidency. He has more in common with Dwight Eisenhower than with Bill Clinton, for example.
Their hatred of Obama is so strong that my guess is they will swallow their distaste for Romney and get behind Mr. Inevitable when he claims the nomination. Their support, though, may be a brew of very weak tea indeed. There doesn't seem to be the heat that would make it stronger.