McCain said in the first debate that Obama doesn`t know the difference between a tactic and a strategy. Looking at the campaign so far, I would say that it is probably McCain doesn`t know what a strategy is.
Obama has done well because of a clear message "change we can believe in". The things he has been talking about lately regarding the economy, is the same things he has been talking about all a long.
We haven`t seen any real changes with McCain and issues either. The difference is message and sticking with the message.
This summer, McCain tried to get Clinton voters and tried to make a spin about Obama having a women problem, he is sexist etc. It didn`t work at all, then McCain tried to use the celebrity-card and he is unexperienced, that actually helped McCain a bit in the polls. But, the DNC was a success, both Clintons helped Obama and McCain had a problem. What did he do? He got Palin as his running-mate, why? To rally his base and probably as a desperate attempt to get the women back.
That did help him a little bit short-term, but probably not as much as some people think, his improvement in the polls was probably more about the RNC....
Then Palin started to talk, the earlier experience-card against Obama was taken off the table and people where talking about how unexperienced Palin was. McCain tried to paint the media and Obama-camp as sexist again.
Then we had the financial-crisis and Palin talked even more. McCain didn`t know what to do, since he hadn`t talked a lot about issues earlier, Obama got a solid lead again. What did they? They started this weekend by having Palin bringing up Ayers, Wright and others. The new tactic was "Who is Obama", "Guilt by association"...
That probably didn`t work well, so they are changing their message again.
If you read this, it probably looks messy and is difficult to follow, thats because it is difficult to follow. What is McCain strategy? It doesn`t look like he has one, its taking things as it comes. A little experience here, a little sexist there, some "guilt by association", focusing on the economy,POW, not focusing on the economy,not so much POW anymore, not so much about experience anymore etc etc. There is NO strategy here at all.
The Obama camp on the other hand: Message of change, focusing on issues (economy, energy, Iraq,health-care)and he does a good job of linking the issues together. It also looks like the Obama-camp knows where they should go, which voters to target etc, they have a brilliant ground-game which will help Obama with a lot of voters, but probably the most with AA and young-voters.
I think the biggest difference between the candidates is Obamas brilliant strategy and McCains lack of strategy.