March 3, 2004 05:29 PM EST DENVER - Republican Sen. Ben Nighthorse Campbell, who has been troubled by health problems and a scandal involving a longtime aide, abruptly announced Wednesday that he will not seek a third term this fall. The retirement gives Democrats an open seat to target in November as they attempt to regain control of the Senate, where the GOP holds a majority of 51-48 with one Democrat-leaning independent. Campbell, 70, a Cheyenne tribal chief who is the only American Indian in the Senate, has faced questions about his health since last year, when he acknowledged undergoing treatments for prostate cancer. Last week, he was examined in a Washington hospital after experiencing mild chest pains that turned out to be heartburn. "After spending another night in the hospital, I realize the deteriorating health may hamper my ability to serve," said Campbell. "Doctors have assured me that after treatment for prostate cancer, the recovery rate is 98 percent. But I believe Coloradans deserve a 100 percent guarantee of service." Campbell is the third Republican Senator to retire this year. Five Democrats also have announced retirement plans, and the GOP hopes to pad its majority by winning some or all of a string of Southern seats where the Democrats are stepping down. http://start.earthlink.net/newsarticle?cat=9&aid=D8135OM80_story The control of the senate will be interesting to watch this election season.