In these years, different groups of voters moved in different directions. Suburbanites in our largest metropolitan areas, repelled by the cultural stands of religious conservatives, trended heavily toward Democrats. Voters in rural areas in the South, Great Plains and Rocky Mountains, repelled by the cultural liberalism and environmental policies of the Clinton administration, trended heavily toward the Republicans.
In or around 1995, these alignments froze into place and pretty much stayed there for 10 years. Helping to freeze them were particular personal characteristics of the two dominant political figures of these times, Bill Clinton and George W. Bush.
But now Bush is not on the ballot and Hillary Clinton's flagging campaign has been sending her husband to places like Chillicothe, Ohio. John McCain does not have the Texas swagger and up-front religious commitment that turned many voters away from Bush and his party. Barack Obama does not seem to have the wobbly moral compass that turned many voters away from Clinton and his party.
The demographic factor most highly correlated with voting behavior in 2000 and 2004 was religion, or depth of religious belief. Within each relevant religious group, the more observant tended to vote Republican and the less observant Democratic. That may no longer be the case. Voters may well split along other lines, as voters in industrial states once split along lines of income or union membership, and voters in states with heavy early 20th century immigration split along sectarian lines (Catholic Democrats versus Protestant Republicans).
If I were running the McCain or Obama campaign, I would be doing in-depth polling and focus groups in 30 to 40 states and nationally, as well, trying to determine which voting groups are moving or moveable toward my candidate and which are moving or moveable the other way. I would certainly not be writing off states that were lost by my party's 2000 and 2004 nominees by 5 percent or more, and I would not assume that states they carried by that much were in the bag. It's time to throw out the old map and search for clues to what the new map will look like.