Allahpundit does his best:
Evidence, then, that most troops want out? Maybe! Except … the data doesn’t specify whether the donations came mostly from Iraq or were spread out around the globe, and interestingly, the one branch where McCain leads Obama in contributions is the one most likely to see the hardest action — the Corps. Beyond that, the would-be McCain soldier-donor has a hurdle to clear on his way to his checkbook that the Paul and Obama donor doesn’t. By kicking in to Maverick, he’s making it marginally more likely that he’ll continue to be deployed in the field and away from his family in the future. Even if he agrees with McCain’s foreign policy, thinks we ought to finish the job in Iraq, and is willing to continue serving bravely and well to that end, it’s asking a lot to ask him to pay for the privilege.