STEVEN K. PAULSON, Associated Press WriterWednesday, September 25, 2002 ©2002 Associated Press URL: http://www.sfgate.com/cgi-bin/article.cgi?f=/news/archive/2002/09/25/politics1715EDT0733.DTL (09-25) 14:15 PDT DENVER (AP) -- Citing an ongoing "threat" to the nation, Republican Rep. Tom Tancredo said Wednesday he will no longer be bound by his pledge to limit himself to three terms. Tancredo, who is seeking a third term this fall, made his announcement in a letter to supporters that was posted on the Rocky Mountain News Web site and later obtained by The Associated Press. In the letter, Tancredo said he is concerned about a challenge facing the United States. "It is my...