Kansas Republican Senator Pat Roberts announced Friday that he would not seek a fifth term in 2020. The decision is not a complete surprise. At age 82, Roberts is the fifth oldest* member of the Senate. His last reelection campaign, in 2014, was difficult. He first had to fend off a Tea Party challenge to win renomination; he won that race by less than 8%. Roberts then won a surprisingly competitive general election against independent Greg Orman.
A number of names have already emerged as possible replacements. These include Secretary of State Mike Pompeo - a former member of the U.S. House from Kansas, current U.S. Rep. Roger Marshall, and outgoing Gov. Jeff Colyer. Whomever emerges will likely be favored - the state has not elected a Democratic Senator since George McGill in 1932. McGill left the Senate in January, 1939 after losing reelection. The subsequent 80 year period of single-party Senate representation in Kansas is the longest such active streak in the country.
Roberts is the 3rd^ member of Congress to forego the 2020 election cycle. Fellow GOP Sen. Lamar Alexander announced his retirement last month. In the House, North Carolina Republican Rep. Walter Jones is also leaving.
*Oldest Senators by date of birth: Dianne Feinstein (D of CA is 85), Chuck Grassley (R of IA is 85), Richard Shelby (R of AL is 84), Jim Inhofe (R of OK is 84)
^In addition, Utah Republican Rep. Rob Bishop said back in 2017 that his 9th term - the one that began yesterday - would be his last. However, no "official" announcement has yet been made.