Arizona was admitted to the Union on February 14, 1912. U.S. senators from Arizona belong to class 1 and class 3 and are popularly elected for a six-year term beginning January 3. Elections are held the first Tuesday after the first Monday in November. The state's current U.S. senators are Democrats Mark Kelly, serving since 2020, and Ruben Gallego, serving since 2025. Carl Hayden was the longest serving senator, served from 1927 to 1969. In total, only 15 individuals have ever served as a Senator from Arizona.