Sen. Jeff Merkley, D-Ore., on Monday hammered 2016 Republican presidential candidate Donald Trump for calling for the U.S. to ban the entry of Muslims, calling it “the single worst idea … ever” from a presidential candidate. “It is inconsistent with our American values, it is inconsistent with our national history,” Merkley said. “… This type of irresponsible statement endangers our national security rather than strengthening it.”