ATLANTA — Georgia’s Republican Senate primary runoff pits a multimillionaire businessman who’s never held public office against a congressman who has spent decades on Capitol Hill, and both worked to frame the match to their advantage Wednesday and draw support from three candidates who didn’t make the cut. Former corporate CEO David Perdue, a cousin of former Gov. Sonny Perdue, blasted Rep. Jack Kingston as a “career politician” who’s already had his chance to tackle challenges such as the $17 trillion national debt.