The 1926 United States Senate election in Colorado took place on November 2, 1926. Incumbent Republican Senator Rice W. Means ran for re-election, but he was defeated in the Republican primary by Charles W. Waterman, a prominent attorney and party leader. In the general election, Waterman faced former Governor William Ellery Sweet, the Democratic nominee. Despite the nationwide Democratic trend, as well as the landslide victory for Democrats in the gubernatorial election, Waterman ended up defeating Sweet by a thin margin. Waterman would not end up serving a full term in the Senate, and died in office on August 27, 1932.
At the Democratic convention, a crowded slate of candidates was slightly winnowed down. Paul P. Prosser, a prominent Denver attorney who had previously been elected as the Howard County, Missouri, Prosecuting Attorney, placed first with 569 1/2 votes. He was followed by former Governor William Ellery Sweet with 279 1/2, former State House Speaker Harry L. Lubers with 133, and former labor leader Frank J. Hayes with 121. Attorney H. C. Fink received only 18 votes and was eliminated.[5] Shortly after the convention, Lubers dropped out, concluding that he lacked the financial resources to compete in the primary.[6] Sweet ended up defeating Prosser and Hayes by a decisive margin, though he fell just short of winning a majority.