Mitt Romney’s retirement shines a glaring spotlight on the potentially bleak future of the Senate’s ideological center in both parties. If Joe Manchin and Kyrsten Sinema follow him out the door, it will get worse.

Manchin, a centrist Democrat, and the Independent Sinema are both still mulling whether to run again. Like Romney, they could be replaced by senators on either end of the ideological spectrum — almost surely a Republican in Manchin’s West Virginia.

And as maligned as Romney, Manchin and Sinema are by one party or the other’s faithful, the possible 2024 departures of two or three of them would change the Senate, which passed several notable bipartisan deals in the last Congress.

“You lose the center, you lose the moderates, you’re screwed. You really are screwed,” Manchin said in an interview. “I’m hoping the voters will wake up.”

It had become cliche to bemoan the Senate’s increasing partisanship over the past two decades, a period of fewer big bipartisan deals, endless procedural delays and episodes like the GOP’s 2016 Supreme Court blockade. Then, for two years under a 50-50 Senate, President Joe Biden found some legislative success by letting the chamber work its will.