Benghazi, Libya (CNN) -- Libyan opposition leaders received a major morale boost Friday as a top U.S. senator made a surprise visit to the rebel stronghold of Benghazi and urged greater American involvement in the bloody campaign to oust longtime strongman Moammar Gadhafi. The visit from Arizona Sen. John McCain came a day after the United States said it was deploying predator drones to Libya. (snip) He said he was against U.S. troops on the ground -- echoing Obama administration policy -- but argued that Western powers need to do more to "facilitate" the delivery of weapons and training for...