Congress was explicitly told they could not do this by the DOJ, but news weren't clear on the legal reasoning, relaying instead the handwavy explanation by Barr

Congress was explicitly told they could not do this by the DOJ, but news weren't clear on the legal reasoning, relaying instead the handwavy explanation by Barr on the popelike infallibility of the president's office. I'm really curious about the actual legal reasoning behind this, it's got to be a fascinating read.