Senator Roy Blunt (R-M.O.) announced that he would not seek a fourth term in the U.S. Senate when his current term ends in 2022. 

A host of Missouri Republicans expressed interest after Blunt’s exit from the race. Most prominently, former governor Eric Greitens, who resigned amid scandal in 2018, declared that he would run for the seat. Missouri Attorney General Eric Schmitt also announced that he will enter the primary. U.S. Reps. Ann Wagner and Jason Smith have not ruled out a 2022 bid. 

On the Democratic side of the aisle, the race is more fluid. Two of the most prominent Missouri Democrats, former senator Claire McCaskill and former Missouri Secretary of State Jason Kander, quickly made clear they would not run. 

State senator Brian Williams, former state senator Scott Sifton and Kansas City Mayor Quinton Lucas are among those who have signaled interest in seeking the Democratic nomination. 

Blunt’s announcement comes amid a wave of retirements among senior Senate Republicans. Senators Portman (R-Ohio), Toomey (R-Penn.), Burr (R-N.C.) and Shelby (R-Ala.) also announced that they will retire in 2022 rather than seeking another term. Widespread speculation persists that Sens. Grassley (R-Iowa) and Ron Johnson (R-Wis.) may retire as well. 

These retirements complicate the map in the battle for Senate control in 2022. With both parties holding 50 seats, even a single seat change can be enough to flip control of the Senate. Though Missouri has swung to the right in the last decade, and Trump won it by more than 15 points, open seats are generally viewed as more competitive than seats held by incumbents. 

Moreover, there have been concerns that 2020 could repeat the volatile 2010 and 2012 Senate Republican primaries. In those cycles, Tea Party favored candidates won Republican primaries against more moderate candidates in multiple races, including Missouri. These more polarizing candidates allowed embattled Democratic incumbents to secure unlikely victories even in Republican-leaning states as Claire McCaskill did in 2012. 

Blunt’s retirement certainly sets the stage for a more turbulent Senate race in Missouri than previously expected.