U.S. Attorney General William Barr says that President Trump should be able to end an investigation of himself if he (Trump) thinks the investigation is unfair. So any president would be able to do this, making a president above the law?
By extension, Barr as the top cop would be able to extend this courtesy to himself, putting himself above the law. But wait there's more: Barr then would be able to extend that to his Republican senator friends or anyone else whom Barr felt had properly inserted their nose.
Has anyone noticed how Trump has gone after the leadership in all our institutions? The effect is to weaken those institutions. This is similar to what Putin did. He did away with high level institutions of government in Russia so that no one would be close to threatening his power.