Asked by Mark Halperin in San Juan to say what the biggest difference between him and Romney is, Santorum says:

“On so many fronts, there could be no person in this country we could nominate who would be any worse on taking on Barack Obama on the most important issue of the day, ObamaCare, than Gov. Romney. And it’s the equivalent of malpractice to nominate someone who gives away the most important issue in this race.”