I figure he was offered either a large cash payment, committee after election, sinecure after retirement - or perhaps plain old blackmail.
Still, he’s not to be trusted.
All of those are possibilities. Could be horse trading going on. It is a possibility that he sees this an easy first step to rebuild his reputation in Utah and (in his mind) burnish his resume to run for Prez again in 2024. Yeah, I don't think that will happen either. But as someone has said, once a person gets the Presidential fever it is hard to get rid of it.
But I agree, there is no way we could trust him.