When was the last time the VP was a Popular Governor™?
Why would a Popular Governor™ resign his job where he does things to take a job where he does nothing?
Technically, Palin was a popular Governor.
Baker seems unlikely to be chosen.
He doesn't have particular appeal to any group. Other Governors are more experienced, and may help more in major swing states. And he's unlikely to stay popular when he becomes a partisan attack dog on a national ticket.
For Baker to be seriously considered for the ticket, he'd have to emerge as an effective national surrogate for the party.
