Barack Obama is leading Hillary Clinton by 51 percent to 44 percent in North Carolina with 3 percent undecided, according to a Research 2000 poll conducted April 29-30. The margin of error is 4.5 percent. An InsiderAdvantage poll earlier today had Clinton coming back from a double-digit deficit to edge Obama 44 percent to 42 percent, within the 3.8 percent margin of error. But that poll had a much large undecided bloc at 14 percent.