And I think I know why. Even with the lowest-key endorsement released late last night, here's how the Associated Press wrote it up:
Former presidential hopeful Rick Santorum urged his supporters to back fellow Republican Mitt Romney's campaign Monday in a late-night email that ignored that Santorum once called Romney the "worst Republican in the country" during their bitter contest.
Santorum, a former senator from Pennsylvania and a newly minted celebrity among conservatives, said that the one-time rivals would unite to deny President Barack Obama's re-election. But in a nod that the wounds had not yet healed, he reminded his supporters of the deep differences between the two and that misgivings had not yet abated.
"The primary campaign certainly made it clear that Gov. Romney and I have some differences. But there are many significant areas in which we agree," Santorum wrote, citing common ground in economic, social and foreign policy.
Whatever their differences, this gives Santorum a good six months to convince Romney that he'll make a great HHS Secretary, right?