For everything people criticize the campaign for, they are doing A LOT of things right. Also, it has always been a good rule that you don't attack your opponent when you're ahead. It just drives down your favorables. The longer Obama keeps the perception of the high ground, the more people will move in his direction. It worked against Hillary and it will work against John McCain.
At this stage in the race: favorability, values, and strength on particular issues are the only polls that matter. Head-to-heads do not. You can see with the number of undecideds slowly moving down that people are being more willing to make a final judgement so now is the time to solidify your image which is what Obama is doing. When that's sufficiently done, then he can rip McCain in the debates and onwards until the election.
