There's a simple answer to the question, I think. He's going to be the next governor of Iowa, assuming that there are no stunning surprises next week and Chet Culver, the Democrat, doesn't mount a miraculous election year comeback.Vander Plaats supporters are dragging out polls that show him doing well against Culver. Well, that's fine, but you do know there's a primary first, right? Who cares about the general if you can't even win the primary?
Indeed, even as the last previous Republican gubernatorial nominee ahead of the Iowa caucuses, Branstad and his team would have quite a bit of influence over the field operation that a candidate Sarah Palin would need to recruit to win there
If you're thinking about running for president, and I think Palin really is thinking about running for president, you don't get on the wrong side of the guy who will probably be governor during the caucuses by endorsing his opponent, no matter how conservative and Tea Partyish Bob Vander Plaats seems to be. By the way: Vander Plaats's biggest proponent: Mike Huckabee, whose campaign he co-chaired in '08.
As for the Iowa Presidential election, I don't honestly get what the big deal is. Huckabee won Iowa. He lost the election big time. For Palin it may be essential to make a statement or something, but I don't put all of my eggs in the Iowa basket.