The 87-year-old Oklahoma Republican was elected to another six-year term in 2020, but has missed more votes than usual recently and told reporters in December his wife has been sick. His decision to step down will surely fuel a competitive Republican primary to succeed him in ruby-red Oklahoma.

Inhofe is expected to serve the remainder of the current Congress and to announce his retirement sometime next week. He’s a longtime top Republican on the Senate Armed Services Committee.