Not that I ever thought I'd be defending Santorum but this is the second time I've had to point this out.

That comment from Santorum was taken WAY out of context. What he said was that Romney was the worst Republican candidate to pit against Obama ON THE SUBJECT OF HEALTH-CARE - because Romney had enacted his plan in Massachusetts that became a model for Obama's plan.

In other words, Santorum was talking about ONE PARTICULAR ISSUE - not the entirety of the candidate's views.