Alan Keyes, a Republican whose two previous runs for president ended in failure, is making a third try for the White House. The Maryland conservative announced on his Web site that he filed paperwork with the Federal Election Commission on Friday to make his candidacy official. He joins a crowded Republican field of nine candidates and is scheduled to participate Monday night at a debate involving lesser-known candidates in Florida. Keyes, a former State Department official under President Reagan, made unsuccessful presidential runs in 1996 and 2000. He also has been a Senate candidate from Maryland, and, in 2004, he...