It's real! Time's Karen Tumulty has a good rundown of how Romney--and even the WSJ op-ed page--are starting to take swipes at the Arkansas Governor:

If you are looking for signs that a dark horse is moving up in the presidential field, there is a more telling indicator to watch than poll numbers. It's when the opposition decides he is becoming enough of a threat to take a shot at him. That's why there was special signficance, an arrival of sorts, to Mitt Romney's seemingly offhand observation Friday in an Iowa Public Television interview that Mike Huckabee had supported "special tuition breaks to the children of illegal immigrants." It marked the first time that the GOP frontrunner in Iowa had ever singled out Huckabee for an attack.

"I must be doing well," Huckabee said Saturday morning, when I told him what Romney had said.
Jason Zengerle