Senator Joe Manchin, a moderate Democrat who’s served in the upper chamber since 2010, announced on Thursday that he will not seek reelection.

“To the West Virginians who have put their trust in me and fought side by side to make our state better – it has been an honor of my life to serve you,” Manchin wrote on X. “Thank you.”

“I will not be running for re-election to the U.S. Senate, but what I will be doing is traveling the country and speaking out to see if there is an interest in creating a movement to mobilize the middle and bring Americans together,” Manchin said in a video address.

Manchin has resisted the Democratic party’s leftward push in recent years, speaking out against progressive efforts to weaken the filibuster and pack the Supreme Court.

“I know our country isn’t as divided as Washington wants us to believe,” Manchin said. “We share common values of family, freedom, democracy, dignity and a belief that together we can overcome any challenge.”

The coal-state lawmaker has also emerged as a vocal critic of Biden’s green-energy agenda.