Lumbee tribal members overwhelmingly voted down a constitutional amendment Tuesday that would have given tribal leaders more power over casino gaming development. Nearly 10,000 enrolled tribal members cast ballots across 21 precincts and through absentee voting in Robeson County. Opponents argued the amendment would concentrate power among tribal leaders and remove a referendum voting system already in the Lumbee constitution. Tribal leadership backed the measure as a way to speed up plans for a proposed Lumbee casino resort near Interstate 95.