Please define to me exactly what political positions of Andrew Sullivan's you believe are 'progressive'.
Pretty much everything he writes is a thinly veiled attack on conservatism. He supports a flat tax - just not THAT flat tax. He supports Republicans - just not THESE Republicans that are on the ticket. He supports war against Islamic terrorists - just not the way we're fighting it. He supports religion - just not in any public place. He opposes abortion as morally wrong - but supports it being legal. Frankly I don't think he has any honest opinions except for his support of gay marriage.
One can for a time pretend to be a conservative with issues against certain conservative positions or people, but when one purports to be conservative while attacking virtually every conservative proposal and candidate, with exactly the same criticisms as the avowed liberals, it becomes abundantly clear that one is merely making a career of being a useful if dishonest tool for the left. It amuses us that you guys continue pretending that the charade is the reality long past its expiration. "See, Andrew Sullivan is a conservative and he agrees with me" may still be comforting, but it's long since stopped fooling anyone who does not wish to be fooled for their own ulterior motives.
A conservative who always agrees that the liberal is the best candidate and that the liberals are on the correct side of every issue is simply a liberal with a truth issue. I think the left is correct on many issues, but you don't find me pretending to be a leftist because on balance, I am a conservative. I could simply claim to be a liberal with principled objections to some liberals and some liberal policies, but no one can have any valid points if they are attempting to gain credibility by pretending to be on the other side except for this one little issue, over and over and over.