South Carolina Sen. Lindsey Graham, who’s taken on tough tasks from immigration reform to climate change, faces another one as he calls for spending billions of dollars overseas on unpopular foreign aid programs that he insists are vital to U.S. national security. With Congress facing mandatory spending cuts and previously sacrosanct military programs on the chopping block, Graham is trying to protect funding for foreign aid even as most Americans oppose it – 71 percent in a recent poll – and other Republican leaders call for focusing U.S. resources at home. “It is a tough sell, but you can be...