I think that McCain’s vulnerabilities on immigration in the general election are exaggerated, because we haven’t seen much electoral evidence that Americans actually vote on the issue in large numbers, however fired up about it they may be. Even if this remains a big problem for him, however, I really don’t see how one could argue that Mitt Romney, Fred Thompson, or Mike Huckabee would have been stronger general election candidates for the GOP. Romney had the flip flop/plastic man problem, Thompson had the “fire in the belly” issue, and Huckabee didn’t have much appeal beyond social conservatives. And as I noted, by the time voting started, Giuliani’s post-9/11 star had faded. McCain is an imperfect candidate, for sure, but he was the most electable in a field of flawed candidates.