Rob Portman is a smart guy, but would be easy to attack for his work in the Bush Administration.
I’ve been saying that Portman is a likely VP pick for Romney (if, God forbid, he ends up receiving the GOP nomination as seems extremely likely), given that just about all of the other first-tier potential runningmates are Catholic, and Romney needs a Protestant in the ticket so as to assuage the fears of some Protestant voters wary of his Mormonism. Marco Rubio, Bob McDonnell, Paul Ryan, Susana Martinez, Bobby Jindal, Rick Santorum, Jeb Bush, Newt Gingrich, Chris Christie ... Catholics all. It’s amazing how we’ve had only one non-Protestant in the 39 GOP presidential tickets since the party was founded in 1854 (Catholic William Miller, Goldwater’s runningmate in 1964), yet this year the party’s presidential nominee will be either a Mormon or a Catholic and nearly all of the best VP candidates are Catholic.
Other than Senator Portman (who is smart, experienced and from bellwether OH, so he would be on anyone’s shortlist), the only top-notch VP candidates who are Protestant are Gov. Scott Walker of WI (who currently is too busy with his recall election to entertain the possibility of running on a presidential ticket, but hopefully that problem will go away soon), former MN Gov. Tim Pawlenty and current SC Gov. Nikki Haley. Of those, Portman seems to me to be the likeliest choice.