If Romney decides he needs someone with government, legislative experience who can still appeal to the base...Sen. Thad Cochran (Mississippi).
If Romney decides he needs a minority to avoid the GOP being seen as a 'white man's party'...Gov. Susana Martinez (New Mexico), Rep. Allen West (Florida), or Gov. Luis Fortuno (Puerto Rico).
If Romney wants a 'business experience' type person...businessman Herman Cain (Georgia).
If Romney wants someone who will 'do no harm'...Fmr. Gov. Tim Pawlenty (Minnesota).
If Romney wants someone from a swing state...Gov. Brian Sandoval (Nevada), Fmr. Sen. Wayne Allard (Colorado), Gov. Bob McDonnell (Virginia), Sen. Richard Burr (North Carolina), Sen. Robert Portman (Ohio), or Gov. Tom Corbett (Pennsylvania).
That would be my short-list. I wanted it to be short but it really didn't work out...if I really had to pick, I would say Romney/McDonnell.
McDonnell is okay, but as a first term governor and no capital hill experience, voters will be skeptical about his readiness for the presidency in the event of an immediate emergency. Romney is also a one-term governor, so he will at least be looking for more Capital Hill experience in his vp similar to Cheney (CoS, etc.) or Biden (old Senator).
