Willie P. Mangum (1792-1861) became a senator from North Carolina in 1831 as a Jacksonian Democrat but soon gravitated toward President Andrew Jackson's opponents in the Whig Party. He changed his position on some of the major issues of the day, most notably by dropping his opposition to the Bank of the United States, an issue so contentious that it resulted in the Senate censuring Andrew Jackson. Mangum insisted that the main issue was not "bank or no bank" but "constitution or no constitution." The North Carolina state legislature then ordered Mangum to vote for Jackson's programs, but he rejected the notion that legislatures could instruct U.S. senators. Despite his political defection, Mangum was a powerful debater and campaigner who repeatedly won reelection. He served as president pro tempore of the Senate from 1842 to 1845.