"I made, I hate to say it, a calculated political decision that Romney was the stronger horse and had a better chance to win Super Tuesday with the resources he had," Santorum said on Meet the Press Sunday. "I would have loved to have Mike Huckabee out there, but I made the political judgment, right or wrong, that [Romney] had the best chance to stop John McCain."
Santorum also noted that he wasn't exactly an early supporter – and that his endorsement didn't do much for his candidate.
“I endorsed him actually seven days before he dropped out of the race," he said.
Santorum's endorsement of Romney may seem like an odd choice now, given the positions that Santorum says he holds most important. (By 2008, Romney had already signed the Massachusetts health-care bill into law, had supported the court when it legalized gay marriage, and had in the past supported abortion rights.)
But though he's the only current candidate who backed Romney, other GOP candidates also had notable endorsements in 2008.
"He's a results-oriented leader," the Texas governor said when he made the endorsement at Giuliani's side, adding that Giuliani was "best equipped to make the tough choices for a country at war." He also emphasized the importance of executive experience for a president – a theme he has continued in touting his own experience.