Except that Romney isn't stupid; his entire political career, he has run as whatever he thought people wanted in order to win, then threw a shit ton of money at it to guarantee victory. He has to know that while Obama is unpopular and the economy sucks, the country is becoming more socially liberal (gay marriage and weed legalization are both now polling with a majority in favor of if I remember correctly) and that hitching his horse to a platform that is going to make Rick Santorum happy isn't a winning proposition, even in this shitty year. Really, he was undone by all of the knives in the primary fight, and what I think will end up having killed him is Obama successfully painting him as Thurston Howell III.
edit: fuck, I just realized I was arguing with someone so out of it they thought Giuliani had a chance of being VP. Please forget that I ever responded.