There are quite a few vulnerabilities that leave Santorum exposed on the right if Romney were willing to exploit them. On role of government and fiscal issues, Romney
could criticize Santorum for his votes for NCLB and Medicare Part D. Santorum is in many respects the embodiment of so-called big-government and “compassionate” conservatism, and this was especially true during his second term in the Senate. In other words, he represented everything that conservatives now think went wrong during the Bush years. Hammering Santorum on Bush-era fiscal irresponsibility hits Santorum where he is weakest
with conservative Republicans, and it does so without forcing Romney to risk the backlash of any party faction. If Romney tried to make an issue out of Santorum’s record on social policy or even foreign policy in terms of electability in the general election, this has the potential of angering cons uencies Romney wants to placate. Pointing out that Santorum has no credibility as a fiscal conservative would be effective, and unusually for something coming from the Romney campaign it would also have the virtue of being true.