Republican John Cowan, a neurosurgeon and small-business owner, is projected to win Georgia’s 11th Congressional District, according to Decision Desk HQ, defeating Democratic Woodstock attorney Chris Harden in the open race. Cowan led Harden 53.8 percent to 46.2 percent with 76 percent of the vote reported by DDHQ as of 9:17 p.m. EST Tuesday. Cowan…