A lot of McCain’s critics have been arguing that he won’t motivate the base and thus can’t win in November. Whether he can win over enough conservatives to win the primaries is an open question. But I think he would be in pretty good shape in the fall. No question, some conservatives would sit out the election. But the senator has very high favorability ratings among Republicans. And I think it is safer for him to dissent on a great many issues that conservatives care a little bit about than on a few about which they care intensely. With the great exception of immigration, McCain’s heterodoxies are not issues that conservatives tend to vote on. They’re not going to leave a Republican nominee over global warming or campaign-finance reform. The question then becomes how many conservatives would stay home out of disgust at his position on immigration. I haven’t seen any data that make me think the answer to that question is “a lot of them.”