Can Trump just fire Barr and put in someone with integrity and competence?
It's far too late. Even if he put in a patriot, the DoJ is full of swamp rats who will not obey the new head and just run out the clock.
He absolutely can. He could appoint Powell, Giuliani, or Mark Levin as acting AG. But he won't.
He has a strange reluctance to fire swampy obstructionists. It's like he's stumbling around with a kick-me sign taped to his back.
When he *does* finally fire a swampster, he appoints the next one in line to replace them.