Republican Senator Richard Shelby won't seek re-election in 2022.

>In short, momentum matters. And Shelby's retirement adds to the momentum of Republican senators announcing they will not be running reelection in November 2022.

>Although we are just more than a month into the 117th Congress, Shelby is the fourth GOP senator to say he won't run for reelection

https://currently.att.yahoo.com/att/real-reason-latest-senate-retirement-183053529.html

https://www.cnbc.com/2021/02/08/richard-shelby-longest-serving-alabama-senator-wont-seek-reelection.html