Romney stays unscathed

Maybe Mitt Romney should look warily over his shoulder, lest a political calamity befall him, too.

Continuing President Obama's political good fortune, a growing list of possible Republican opponents in 2012 is falling by the wayside, often due to self-inflicted wounds.

Two weeks ago, Senator John Ensign of Nevada admitted a messy extramarital affair with a former campaign staffer, likely taking himself out of the running.

This week, Alaska Governor Sarah Palin took more hits in a scathing piece in Vanity Fair magazine in which unnamed aides to Senator John McCain, who picked her as the GOP vice presidential nominee last year, basically said she was not ready for prime time.

And, of course, South Carolina Governor Mark Sanford keeps digging his political grave deeper and deeper, confessing on Tuesday to indiscretions with women other than his Argentinian mistress, whom he called his soul mate.

Romney, the former Massachusetts governor who ran last year for the Republican nomination, has kept himself largely unscathed since Obama took office, even as he has kept himself omnipresent on cable TV. He has continued raising money for fellow Republicans, collecting chits along the way. He has burnished his foreign policy credentials, his weak area last year. In an attention-grabbing speech last month, he assailed Obama's national security strategy, asserting that the president is endangering America and unnecessarily apologizing on the country's behalf.

As the Republican field opens up before him, Romney's continuing strength could help explain why Democratic groups criticize him at every opportunity, often reviving the accusation that he will flip-flop on issues when to his political advantage.