I don't think the voters have such nuanced reactions to the surge argument. The gist of McCain's push is that things are better in Iraq now than they were, and on that the stuff in the main stream media lends him support. Obama has to watch out for this; he can get hurt taking a position hostile to the surge, which will be seen as refusal to admit that things are in fact better than they were. Obama was better off a couple of weeks ago when he was saying security-is-better -- and that means we can start withdrawing.

Ending a war is one of the trickiest issues any presidential candidate can face. See for examples: John C. Fremont, the Republican [sic] candidate in 1864, who ended up withdrawing from the race because Lincoln's 'surge' -- the march into Georgia with Atlanta falling in the summer of '64 -- showed positive results. Or, Eisenhower in 1952, who didn't say 'we've won' or 'we've lost' but only "I will go to Korea." That worked for him because he had such a high personal favorability rating.