I think Manchin is immovable.
He's got much to gain scuttling all the Dem business, rewarded now and after the Senate. He wants no re-funding of the IRS.
and will lose many $Ms if he votes with the Dems. How can the Dems counter that?
MSNBC found Manchin in early 2021 wanting a $4T infrastructure deal, he was probably telling the oligarchy he was open to be bribed, and he was bribed.