The West Virginia independent, one of the staunchest defenders of the potent delay tactic in the Senate, told CNN on Tuesday that he wouldn’t back her candidacy now — despite signaling earlier this month he was getting ready to do so.

“Shame on her,” Manchin, who is retiring at year’s end, said in the Capitol. “She knows the filibuster is the Holy Grail of democracy. It’s the only thing that keeps us talking and working together. If she gets rid of that, then this would be the House on steroids.”

Now that Harris has vowed to gut the filibuster on this issue, Manchin said he wouldn’t back her for president.