McCain is trailing Obama in opinion polls (see http://www.rasmussenreports.com/), but I think that this is the typical result of the enthusiasm for the nomination. However I don't know if Obama would be a successful candidate or not in November. In order to win he will need to hold all the States Mr. Kerry won in 2004 and actually win some more States. Take a look to my analysis.
The most swinging States that Obama could win are, in my opinion, Florida, Ohio, Iowa, Colorado, Nevada and New Mexico. I actually don't think that he can win Florida, Ohio and Colorado, all three States were McCain will be a strong canidate, and if he wins the three remaining States, McCain will win the general election with 269 e.v. over the 268 e.v. of Obama.
Moreover McCain could easily retain those three States mentioned and win a few more States Mr. Bush did not win in 2004 among Maine, New Hampshire, Pennsylvania, Michigan, Wisconsin and Minnesota. In these States Bush was close to victory and McCain will be a strong candidate. If he retains all the States Bush won in 2004 and wins some more States, he will win by a landslide.
It seems to me that Obama is the strongest Democratic candidate in Southern and Mountain states (states that McCain will definitely win, although with a smaller margin than Mr. Bush in 2004), while McCain is the strongest Republican candidate in the North-East, in industrial states (like New Jersey, Pennsylvania and Michigan), in the Mid-West and in California.
It will be a close race, but it seems to me that Obama is actually gaining strenght where he doesn't need it, while being weaker in swing states like Pennsylvania, Ohio, Michigan, Wisconsin and so on.
It is too early to make forecasts, but I definitely think that it will be a close race in much more states than in 2004 and that, in that kind of race, McCain is a strong candidate. Obama has much to loose if the red-blue scheme disappears in November. The 50-states strategy will help Mr. McCain, not Obama, who needs not to loose any of the states which Mr. Kerry won in 2004.
(Images: McCain: top, Obama: below)