CONCORD, N.H. (AP) — Republican candidates have given wildly differing responses to South Carolina Republican Sen. Lindsey Graham’s plan to ban abortion nationwide at 15 weeks. A Republican Senate challenger in Colorado describes the proposed ban as “reckless.” GOP Senate contenders in Georgia and Arizona have quickly pledged their support. And in Pennsylvania and Nevada, Republican Senate nominees are avoiding taking firm positions. The explosive issue threatens to upend the GOP’s overwhelming political advantages just eight weeks before Election Day. Democrats have been quick to point to the measure to warn that handing control of Congress to Republicans could lead to a broader erosion of rights.