The more I think about this race, the more I feel like even if Obama somehow loses the election, his coattails will add to the Democrats Senate advantage in Congress. If we look at this senate map it is entirely possible given the competitive senate seats could flip in the general even if Obama loses the election.
Adding North Carolina, Texas, Alaska, Colorado, Oregon and New Hampshire will bring a 57/42 advantage in the Senate with similar results in the House. The last seat... Arizona. Governor Janet Napolitano will likely appoint a democrat to President (eek) McCain's Senate seat bringing the majority to 58.
This would spell an even greater disaster for the Republicans as McCain may prove to be the GOP's version of Jimmy Carter. McCain would be largely neutered as it is likely the Congress may pass legislation over his head quite frequently. 2012 will leave the GOP with no viable presidential candidates and even more Republicans in Congress on the hot seat.