U.S. Sen. Richard Burr's approval rating remains below 40 percent, which might ordinarily be bad news for a politician, but he's still ahead of any of his potential Democratic challengers in next year's election, according to a poll released Friday. The approval rating for Burr, a Republican, was 38 percent, according to the survey by Public Policy Polling, a Democratic firm. In matchups against possible Democratic opponents, Burr beat: U.S. Rep. Bob Etheridge, of Lillington, by 41 to 34 percent. Secretary of State Elaine Marshall, who officially launched her candidacy this week, and former Lt. Gov. Dennis Wicker, by the...