McCain's extremism pales next to Hillary's. Hillary's extremism pales next to Obama's. I think I now have absolutely no problem voting for McCain now. Only with his independents can we beat the democrats with all the advantages of race, gender and talk of change and hope. McCain is no constitutionalist, believes in Global Warming, and is soft on immigration but he loves his country. He is patriotic.
Obama is the ultimate culmination of left wing 60's anti-American and anti-Christian radicalism and that is why he plays it so close to the cuff. Hillary is a screeching ultra-feminist socialist radical but I don't think she's nihilistic.
Obama is the Muslim Manchurian Candidate.
Honestly I can’t tell who is or has the most extremism in them. The author/sponsor/cosponsor of the most extremism in legislation over the past 10 years has been McCain. I do not know if he is corral-able. He has less discipline than either Hillary or Obama.