The seven Republican candidates vying this year for the state’s U.S. Senate seat being vacated by Saxby Chambliss have more than a few things in common. But during a debate Saturday night at Brenau University’s Pearce Auditorium attended by a few hundred residents and political observers, each candidate took pains to highlight the nuances that separate them from the others on the bread-and-butter issues that energize GOP voters. Hosted by the Georgia Republican Party, the third debate in a series of seven set the stage for the May 20 primary that pits several Washington and state political veterans against a few upstarts looking to upend the dynamic that has seen Congress’ approval ratings plummet.