The Hurricane has benefited Obama and hurt Romney.
Romney was behind in most of the swing states he needs to win. He needed this time to attack the President and make up ground. In addition, he specifically choose to spend less in the early campaign and blitz us with ads at the end.
But the Hurricane took over the news, locking him out of the coverage. It disrupted his plan at the last minute. People weren't talking or thinking about his ads, they were thinking about survival and their family. Worse, in times of real crisis, people dislike partisan attacks. So Romney had to tone down his talk. Otherwise, he would have looked spiteful.
It also gave President Obama an opportunity to act Presidential. He did a good job. In particular he was praised by Republican Governor Chris Christie, who is a big Romney supporter. Romney, who currently holds no political office, did not have that chance.
Some people have said this doesn't matter. Ask President Bush about Katrina. How the President
The election is still a few days away, but we have more than enough time to get power and transportation systems up and running. This means that poor people will still be able to vote.
Obama would have won anyway, but this prevented a last minute October Surprise, as they say (last minute turn around in a political election)