It’s pretty simple. Romney knows there’s nothing to gain by being the first out of the gate. He sees Palin getting trashed and knows he’d rather let her take all the fire, and slide in when he has to, rather than compete for the spot light so early on.
Palin 49%
Romney 23%
I know it's too early to peak, but he's goin down, not up. When his healthcare numbers start to become the issue, he may as well be a Dem.