Westchester District Attorney Jeanine Pirro confirmed Monday that she will seek the Republican nomination for the U.S. Senate. Pirro?s confirmation will result in a political showdown with Senator Hillary Rodham Clinton who is set to seek re-election next year. Pirro also faces a possible Republican primary involving, among others, Edward Cox, a Manhattan lawyer who is a son-in-law of the late President Richard Nixon. The 53-year-old announced May 23 she would not seek a fourth term as district attorney, but would run for statewide office in 2006. One of Pirro?s top advisers said she planned to tour the state Wednesday to formally announce her decision. Click here for reaction from Westchester County residents. Related story Adviser says Westchester DA Pirro to challenge Clinton's Senate re-election bid