Quite a while back, I decided that Ohio Sen. Rob Portman was the Romney running mate that would cause the most problems for the Democrats, so much so that I superstitiously didn't blog it and hoped no one would catch on - then I saw Charlie Cook say the same thing, and eventually Portman became the perceived frontrunner for the selection. Romney has to win Ohio, and Portman would have a chance to help him there. Portman has experience in domestic economic policy, though some of it is in the Bush administration, so he'd be able to present himself as a moderate, pragmatic figure that could give voters the impression that they are better capable of handling the economy than Obama and Biden.
Who else would have been good? Gingrich's campaign exposed how weak Romney's support is in the South and a liaison with the accent could have helped shore up North Carolina, Virginia, Florida, and even help in places like Iowa and Ohio. Former Texas Sen. Kay Bailey Hutchison - who McCain would have been better off with - would have brought a new, moderate personality to that race. Tennessee Sen. Bob Corker opposed the Libya War and seems to be appropriating some of Ron Paul's policies but he has some legal baggage. I don't think Marco Rubio or Bobby Jindal would have played well for different reasons.
A critique I had of the Obama camp is that instead of letting Romney say he's done nothing to create jobs, he should be traveling to close Congressional districts to campaign against House Republican incumbents who obstructed his jobs bill. Well, now, instead of having a race where the Democratic advantage in presidential politics may, as history suggests, make swing voters vote for the opposing party for Congress, you now have an election year in which House politics is center stage, due to the selection of Paul Ryan. Where you had a disillusioned Democratic base that was apathetic about the election, they will now be out in droves not just to fight Paul Ryan, but to keep his policies from gaining legislative traction. This is, of course, because Romney has no polices of his own that he's consistently advocated, so Ryan is a 'turn key deal' in the policy arena. Much is going to be said about Ryan's Medicare policies, and this is going to affect Senior Citizens' voting patterns and activism not just in presidential politics, but in congressional politics as well.
Overall, Romney should have held out the hope that people would elect him, a rich guy who doesn't tell the truth, flip-flops, runs Bain Capital, the Olympics and Massachusetts because they want his economic experience and decide that his expedient flexibility on the issues may be appropriate to the national situation. Instead he made the election year a referendum on Paul Ryan. I'm pretty sure it's a strategic disaster for him, not as bad as the Palin choice (which I immediately said would lose the election for McCain), and I welcome the focus of executive and legislative races on substantive disagreements on policy.