A new Research 2000 poll shows Obama leading in Missouri by 5 points.
http://www.stltoday.com/...
This changes the composite polling average for Missouri to a virtual tie and moves Missouri up in the pack of states that McCain has to fight to hold on to.
As you can see, Obama is in a tremendously advantageous position right now.
Obama has to hold these states: Washington, Minnesota, Oregon, Wisconsin, New Jersey, and Pennsylvania. Now, some people try to suggest that some or all of these states are in play, but the polling seems to indicate that Obama holds comfortable and stable leads in all of them. Obama has to defend these states to some degree, but for the most part, they appear safe.
Obama has to also hold these states: New Mexico, New Hampshire, Iowa, and Michigan. I think most people agree that these states are a lot more vulnerable than the ones above. Obama currently holds reasonably good leads in the polls in these states, but polling can turn around fast so they need to be vigorously defended. The only current worry here is that Obama’s lead in Iowa seems to be steadily declining since the beginning of the year.
Assuming that Obama’s current healthy leads in the above states hold and he defends them successfully, then he has 264 EC votes. He need only win one of any of these: Ohio, Colorado, Virginia, Indiana, North Carolina, Nevada, Florida, Missouri, South Carolina, Georgia, or West Virginia; or two of any of these: Montana, North Dakota, Alaska, or South Dakota. The current polling in the above states indicates that none of them are necessarily out of reach for Obama. A single poll in most of these states could shift the composite polling average to a near tie (as we saw today with Missouri). Given that he need only take one or two of these 16 possible states, it makes the most sense to go on the offensive in all of them, forcing McCain to defend in depth, and burn resources that he otherwise badly needs to use on the offensive elsewhere.
So Obama has to defend in 4 or 5 places and is free to go on the offensive in 16 others. McCain on the other hand is defending in 16 states and must hold all of them, while having only a handfull of opportunities to go on the offensive. Unless there is some dramatic change in the polling in a dozen or so states in the next 2 months, it's hard for me to imagine how McCain can climb out of this hole.