Democratic Senate candidate Michelle Nunn has nabbed the endorsement of former Georgia Gov. Zell Miller (D), a conservative Democrat who's backed more Republicans than members of his own party in recent years.

Miller, who gave the 2004 Republican National Convention keynote speech endorsing then-President George W. Bush, praises Nunn in a new ad from her campaign.

"She's a bridge builder, not a bridge burner," Miller says in the ad. "Michelle Nunn gives this old Georgian hope."

Nunn has been seeking the center in the conservative-leaning state, as she duels businessman David Perdue (R) for retiring Sen. Saxby ChamblissSaxby ChamblissOPINION: Left-wing politics will be the demise of the Democratic Party GOP hopefuls crowd Georgia special race Democrats go for broke in race for Tom Price's seat MORE's (R-Ga.) seat. Miller, incidentally, endorsed Chambliss in his reelection bid six years ago.