American democracy grows more degraded and ugly by the day. Candidates slander each other without hesitation, members of Congress prostitute themselves for campaign contributions, and the most honorable men and women in Washington are quitting in disgust. Few retirements will hurt Washington more than that of Sen. Bill Bradley (D-N.J.). As he demonstrates in his new memoir, Time Present, Time Past, Bradley is too thoughtful, too dignified, too compassionate, and too diligent to endure six more years of posturing on Capitol Hill. Bradley signs copies of his book at 6 p.m. at Barnes & Noble, 3040 M St. NW. FREE. (202) 965-9880.