It's his ally now.
If you have watch any of the debates, you will see the visceral hatred McCain has for Romney. McCain wants to knock Romney out now in Michigan. He may very well do it. In the meantime, Huckabee has been allied with McCain in going against Romney. And then you wind up with Fred who is trying to knock out Huckabee, his greatest nemisis in what both perceive as their power base, i.e., the South. Finally, McCain is currently ahead in SC and hopes to ride a Michigan victory to a big win in SC.
Romney and McCain have never been allies and never will be.
Personally, I hope the two end up on the same ticket. Though I know that won’t be popular around here according to Fred’s supporters.