Gretchen Whitmer probably will be the nominee to replace Stabenow in 2024 win or lose in 2022 (I don't think Stabenow runs for reelection).
Other than that, Kevin Sitt comes to mind, if he somehow manages to lose in Oklahoma. Jim Inhofe is going to retire or die eventually, and I imagine Sitt would run in a hypothetical special election for that seat.
Stitt is not going to lose in this environment, especially in a state as Republican as Oklahoma, where no Democrat has won a statewide office since 2006. But you're right about his prospects. He could very well succeed Inhofe, and I wouldn't be surprised if Inhofe decides to finally retire when he is next up in 2026, as he will be
92 years old by then.
