The electoral map candidate Barack Obama remade in 2008 appears to be retreating into its familiar patterns. Obama broke the decisive role Ohio and Florida seemed to play in presidential elections, by moving from trench warfare engagement in the two states to a broader battlefield on which Republicans were placed on the defensive in states they’d once taken for granted. And his victories in places where Democrats had fared poorly in recent elections — Indiana, North Carolina, Virginia, the interior West —seemed to validate his strategists’ claims that he had consigned the red state-blue state presidential dichotomy to the bookstore remainders bin.