I think Trump sees the AG's role as one of defending himself against all slings and arrows. That and Trump seems to relish not only defeating people not totally loyal to him but to be vindictive about it. Honestly though that trait was/is part of Trump's appeal to his base. We just hoped it would be applied to democrats.
You nailed it.
And that isnt the role of the AG..but scaramucci praised holder..and we know how holder operated