The 1990 United States Senate elections were held on Tuesday, November 6, 1990, with the 33 seats of Class 2 contested in regular elections. Special elections were also held to fill vacancies. The Democratic Party increased its majority with a net gain of one seat from the Republican Party. The election took place in the middle of President George H. W. Bush's term, and, as with most other midterm elections, the party not holding the presidency gained seats in Congress. These elections featured the smallest seat change in history since the passage of the Seventeenth Amendment in 1913 with only one seat changing parties, and this would happen again in 2022. That election featured Democrat Paul Wellstone defeating incumbent Republican Rudy Boschwitz in Minnesota. To date, this is the last cycle in which Democratic candidates won U.S. Senate elections in Oklahoma and Tennessee. Results summary Source: Clerk of the United States House of Representatives Gains, losses, and holds Retirements Three Republicans retired instead of seeking re-election. Defeats One Republican sought re-election but lost in the general election. Change in composition Before the elections Result of the elections Complete list of races Special elections In these special elections, the winners were elected in 1990. Elections are sorted by date, then state and class. Elections leading to the next Congress In these general elections, the winners were elected for the term beginning January 3, 1991; ordered by state. All of the elections involved the Class 2 seats. Closest races In eight races the margin of victory was under 10%. Michigan was the tipping point state with a margin of 16.3%. Alabama Incumbent Democrat Howell Heflin won re-election to a third term over Republican Bill Cabaniss, State Senator and former State Representative. This is the last time the Democrats have won the Class 2 Senate Seat from Alabama until Doug Jones won the seat in 2017. Alaska Incumbent Republican United States Senator Ted Stevens sought re-election to a fifth term in the United States Senate, which he won easily, besting his opponents in a landslide. Arkansas Incumbent Democrat David Pryor won re-election uncontested. Colorado Incumbent Republican senator William L. Armstrong did not seek re-election to another term. Republican congressman Hank Brown won the open seat, defeating Democratic nominee Josie Heath, former Boulder County Commissioner Delaware Incumbent Democrat Joe Biden won re-election to a fourth term, defeating Republican challenger M. Jane Brady, Deputy Attorney