From Collision 2012, the new book by the terrific Dan Balz:
"...Everyone on the short list had issues, pros and cons. Ryan came with all the controversy surounding his budget and its radical changes to Medicare. Pawlenty lacked the charisma that would help to energize conservatives and make them feel better about Romney. Christie, in addition to pay-to-play, had a personality guaranteed to overshadow Romney. Portman had the Washington experience that Romney lacked, but was tied to the Bush presidency. Rubio was talented but untested. But he had another issue. As a Florida legislator he had brushed up against a financial scandal involving the Florida Republican party. In addition, then-representative David Rivera, a close friend and fellow office-holder, was under federal investigation for for campaign irregularities.. There was no evidence of wrongdoing by Rubio, but among at least some Romney advisers there was concern that Rivera would be indicted before the election, and if that were to happen the story would become a major distraction. Myers said, however, that issue did not keep Rubio off the short list of contenders. "Mitt received a number of completed vets, all of which were viable candidacies, and Marco was one of them," she said.
Those advisers wary of Rivera/Rubio were clearly correct. Even without an indictment, the Rivera scandal popping with revelations in the Herald practically every other day would have been an enormous distraction for the Romney campaign.
--ADAM C. SMITH, Tampa Bay Times