"As Nation and Parties Change, Republicans Are at an Electoral College Disadvantage"
The major take-away here is that Obama won by at least 4 points in enough states to give him 272 electoral votes - enough to win an election. He would still have won without Virginia, Ohio and Florida (or North Carolina, which he lost anyway). That represents a big challenge for the GOP because it is very difficult to move 4% of the electorate.
The same sort of logic applies to the GOP group. Except for North Carolina, Romney won every state by 8 points or more, giving the GOP a solid red 191 that cannot be moved blueward. But that's not as important as the solid 272 blue on the other side of the table.
The good/bad news for America - only 75 electoral votes really seem to be in play.