Being a free-market advocate, I was generally OK (>50%) with what Santorum appeared to advocate in spite of many contradictions. He seemed to have at least a common-sense level of understanding as to why markets are morally good and worth fighting for. However being an Objectivist (laissez-faire capitalist, generally libertarian) and therefore socially liberal, I found his distaste for church/state separation maddening.
However, the real story in his candidacy is the role of moral conviction.
Santorum was not afraid to say what he thought -- and more than that, what he thought was morally right -- and I think many people respected him for his courage. By contrast, Romney tries to be everything to everyone by never offending anyone or taking a stand (Massachusetts health care -- then running as a Republican? Yikes). Moral conviction and integrity, in spite of his flaws, was one of Santorum's strengths, and people saw that. And that is how he got as far as he did.
Still, I doubt I would have voted for him, even though the alternative is horrible. Such is the voting quandary of the classical liberal.
