Many of his former Democratic colleagues now view him as something of a traitor, and Davis himself has emerged as a vigorous critic of the party and President Barack Obama. He’s even taking to supporting GOP candidates. Friends and allies who helped guide his ascent say they no longer talk to the congressman — and some Democrats believe he will leave the party altogether…

For all his talent and promise, Davis always had something of a strained relationship with his party, dating back to his defeat of Rep. Earl Hilliard in a 2002 primary that left him on the outs with the Congressional Black Caucus, whose members publicly supported Hilliard and resented Davis for taking down their friend.

Those long-simmering tensions came to a boil in last year’s Alabama gubernatorial race, a contest in which Davis — with an eye toward currying favor with the Republican voters who dominate the conservative state — sought to bypass Alabama’s Democratic power structure to claim the nomination…

Once a loyal friend and an ally of Barack Obama, Davis has recently broken publicly with the president, as well. In a recent post on POLITICO’s Arena, Davis hammered Obama over his education agenda and suggested that New York City Mayor Michael Bloomberg, a Republican-turned-independent, should launch a 2012 White House bid. Davis told POLITICO this week that he hadn’t decided whether he would support Obama’s reelection.