WASHINGTON, D.C. Yet another U.S. senator has announced plans to retire. This time it's three-term Republican William Cohen of Maine, a GOP moderate, who surprised his fellow Senator by announcing that he is abandoning the increasingly polarized Senate. Cohen cited the budget stalemate as "instrumental in crystallizing this issue for me." Cohen raised party hackles by voting against the GOP's original budget last fall. But his reputation for independence goes back to 1974 when Cohen, then a freshman representative, voted to impeach Richard Nixon. He called it "the most difficult decision of my life." Having served on the Senate Select Committee on Intelligence and as chairman of the Armed Services Subcommittee on Seapower, Cohen plans to pursue opportunities in international trade. TIME's Larry Barrett notes "among several Republicans leaving Congress voluntarily, William Cohen is without doubt one of the brightest and most willing to take thoughtful, independent stands. His departure will be another major loss for the moderates who have sought to get things done, whether on health care, welfare, or attacking the deficit."