United States Senate election in Oregon 1990 Tags: Election.The 1990 Oregon United States Senate election was held on November 6 1990 to select the U.S. Senator from the state of Oregon. Republican candidate Mark Hatfield was re-elected to a fifth term defeating Democratic businessman Harry Lonsdale. thumbnail country Oregon start date 1990-11-06 title United States Senate election in Oregon 1990 Learn more... Loading...