>Has he called it unconstitutional before?
I don't believe he (Trump himself) has.
There was a post or link a day or so ago explaining how RR was not constitutionally authorized to appoint a SC. Here, I think, but maybe somewhere else during downtime on infinity chan.
Trying to remember details, but fuzzy; it had to do with the various staff changes at DoJ and who was eligible in the wake of those changes to assume eligibility (chain of command stuff) for such decisions.
I think Trump may have decided to pull on that string.