I wonder if that might be because you support someone else?
There are key points of conservatism, too, though I am actually somewhat libertarian by nature. If a candidate's record violates one or two-- well ok. But on several points illegal immigration, foreign policy expertise, anti-tax or fee raising, pro-life, and pro-2nd amendment: Romney is deficient or fails. Guiliani fails. Paul fails. McCain fails big time. That leaves Fred Thompson.