The liberal former candidate's backing of the centrist Nunn, who's running for retiring Sen. Saxby ChamblissSaxby ChamblissGOP hopefuls crowd Georgia special race Democrats go for broke in race for Tom Price's seat Spicer: Trump will 'help the team' if needed in Georgia special election MORE's (R-Ga.) seat, is the latest sign top Democrats are lining up to support her candidacy. Dean is a lobbyist at the law and lobbying firm, as is Gordon Giffin, Nunn's top advisor and a longtime Georgia Democratic strategist.

Democrats are hopeful that Nunn can give the GOP a tough race in the red-leaning state.