The elevation of Robert Byrd as President Pro Tempore of the Senate on Thursday makes an 89-year-old former Klansman third in the line of presidential succession. Only Vice President Dick Cheney and new House Speaker Nancy Pelosi stand between the West Virginia Democrat and the White House if President Bush does not finish his term. Byrd was first elected to the Senate in 1958 and is the longest-serving member of the Senate in history. He won his ninth term in 2006 and is now the oldest member of the U.S. Congress. He also served six years in the House. If...