The real issue is not how well Obama or McCain might do in the closely divided battleground states, but that we shouldn't have battleground states and spectator states in the first place. Every vote in every state should be politically relevant in a presidential election. And, every vote should be equal. We should have a national popular vote for President in which the White House goes to the candidate who gets the most popular votes in all 50 states.
The National Popular Vote bill would guarantee the Presidency to the candidate who receives the most popular votes in all 50 states (and DC). The bill would take effect only when enacted, in identical form, by states possessing a majority of the electoral vote -- that is, enough electoral votes to elect a President (270 of 538). When the bill comes into effect, all the electoral votes from those states would be awarded to the presidential candidate who receives the most popular votes in all 50 states (and DC).
Because of state-by-state enacted rules for winner-take-all awarding of their electoral votes, recent candidates with limited funds have concentrated their attention on a handful of closely divided "battleground" states. In 2004 two-thirds of the visits and money were focused in just six states; 88% on 9 states, and 99% of the money went to just 16 states. Two-thirds of the states and people have been merely spectators to the presidential election.
Another shortcoming of the current system is that a candidate can win the Presidency without winning the most popular votes nationwide.
The National Popular Vote bill has passed 21 state legislative chambers, including one house in Arkansas, Colorado, Maine, North Carolina, and Washington, and both houses in California, Hawaii, Illinois, New Jersey, Maryland, Massachusetts, Rhode Island, and Vermont. The bill has been enacted by Hawaii, Illinois, New Jersey, and Maryland. These four states possess 50 electoral votes — 19% of the 270 necessary to bring the law into effect.