For conservatives, the basic appeal of Bush was that he’d be their own Clinton – someone with similar charm and charisma who’d finally be able to deflect the Democratic attacks. They didn’t want him straying too far ideologically, but they were more than happy to give him a lot of room to roam.
Today’s conservatives aren’t looking for another Clinton. They haven’t faced a humbling defeat at Obama’s hands (not yet, at least), and they believe adamantly that rigid adherence to their ideology is a winning national strategy. This doesn’t mean Romney won’t try to distance himself, but if he does, he’ll face a much fiercer backlash than Bush ever did.
Starting with immigration. Watching him move from his primary position is going to be fascinating. It's odd but Romney seems both the most protean and yet most rigid of politicians. My bet is that he remains a captive of a party intent on radicalism at home and abroad. And he will aim to please them.