In 1983, Governor John Spellman appointed Evans to the United States Senate to fill a seat left vacant by the death of longtime senator Henry M. "Scoop" Jackson. Evans won a special election later that year against Mike Lowry and filled the remainder of Jackson's unexpired term, retiring from politics after the 1988 elections. He was not happy as a U.S. Senator; he wrote an April 1988 piece in "The New York Times Magazine", "Why I'm Quitting the Senate", in which he complained of "bickering and protracted paralysis".