Barack Obama threatens to drive political cartographers crazy. By attracting young people and African-Americans, he believes he can turn red states blue and upend our relatively stable political map. Obama may well win the November election on a wave of Democratic turnout and enthusiasm, but he will likely find that states don’t change their political stripes very easily. The 2000 and 2004 elections were remarkably similar. Forty-seven states voted for the same party in both elections. Only New Hampshire, which switched from Republican in 2000 to Democrat in 2004, and Iowa and New Mexico, which moved in the other direction,...