Why did a formerly respected conservative sell his soul to an amoral troll? Because his soul was at stake.
Ah, Bill Barr, we hardly knew ye.
No one is sad that you’re gone. Not the left, who will never forgive you for misrepresenting the Mueller report and exonerating President Trump. Not the hard right, who will never forgive you for betraying their spray-tanned god in the hour of his greatest need. And not the reasonable, rational centrists, either, who thought you were one of them until you showed them that you weren’t.
But all of us who have followed your bizarre second career as attorney general are left pondering one, impenetrable question: Why?
Why did you do it? Why did you even take this job, knowing the kind of man you’d be working for? And why did you then surprise the Washington establishment by not only carrying water for this amoral troll but contorting the truth, eroding the integrity and independence of the Department of Justice, indulging Trump’s basest authoritarian instincts, and even being held in contempt of Congress along the way?
The sycophancy went right to the end. Even Barr’s resignation letter is a gigantic kiss on Trump’s posterior, lauding “the many successes and unprecedented achievements you have delivered for the American people.” Though I guess we can chalk that up to Stockholm Syndrome.
https://www.thedailybeast.com/why-bill-barr-did-it-all-for-donald-trump
Bottom line: Barr is a religious nutjob who was fighting against the "moral decay" of American society.