ATLANTA — Georgia voters heard familiar arguments in the final U.S. Senate debate before polls open, with Republican David Perdue repeatedly trying to tie Michelle Nunn to President Barack Obama and Nunn countering that Perdue is intent on continuing the dysfunction he blames on Democrats. “President Barack Obama said his policies are on the ballot, and in Georgia those policies go by the name of Michelle Nunn,” Perdue said several times. More than a dozen times, he used an attack featured in many Republican TV ads for this midterm election, calling Nunn a “rubber stamp” for the president who lost Georgia twice.