Andrew Gelman has posted several outstanding graphics and analysis of the 2008 election at his Red State, Blue State, Rich State, Poor State blog. In particular I want to call attention to the graphs that show the 2000-2004 and 2004-2008 swings by state (the fourth and fifth graphs in “Election 2008: what really happened“).
The data show that Obama’s victory was not a map-changer; it was mostly a national swing, the result of which was to lift some of the closer states (Colorado, New Mexico, Virginia, Iowa, etc.) over the threshold from “red” to “blue.” Again, that is consistent with the “partisan mandate” I referred to yesterday, rather than with any talk of a “realignment” (in which the underlying demographic electoral coalitions of the parties change). That is not to say there is no evidence for any of the latter. For instance, minority and youth vote turned decisively towards the Democrat. (We won’t know whether that is because of a young and biracial candidate’s personal appeal or partisan realignment till post-Obama elections.) Overall, however, this was clearly mostly a national swing–for the presidency, and most likely for the House and Senate, as well.