You guys are forgetting something. The real question is whether republicans are hurting their own chances at power by supporting the sure, and not whether McCain is hurting his chances. I voted no on the poll, for one obvious reasons.
it's basically impossible for McCain to win the general election if he doesn't get nominated first. He isn't going to get nominated by taking sides with the democrats on the Iraq war. The number of people who support the surge, by coincedence are the exact same number of people who approve of President Bush.
If John opposes Bush on Iraq he wont get nominated. It's true that after he's nominated it will hurt him, but to even get his foot in the door he has to support it.