Why He's "Playing Nice"

The Politico notes that Mike Huckabee is "playing nice" and refusing to criticize his rivals Mitt Romney and Rudy Giuliani.

Is it because he's just a nice guy? Hardly. It's because he knows he doesn't have the money (and likely the support) to go the distance and win the nomination. In reality, he's running for vice president, and it makes no sense for a southerner who's conservative on some social policies to alienate a couple of northeasterners who might want to put him on their tickets.