(CNN) -- Nearly a year after the presidential election, the excitement of Barack Obama's campaign has faded into the reality of an Obama White House. As observers try to determine what time it is in American politics, they arrive at opposite conclusions. To some, said Tulane University political scientist Thomas Langston, Obama is like Jimmy Carter, and the nation will soon hammer the nails into the coffin of a dying Democratic coalition just as voters, tired of the Carter "malaise" era, handed the White House to Republicans in 1980. To others, Obama has come to usher in a new understanding...