It is only a conflict for the judge because judges are supposed to be impartial. Lawyers are supposed to be on one side, so I don't see why his former impartiality would be a problem.

Well, at least you'd get consistent application of the case law!

I believe that under the ABA Model Rules of Judicial Conduct he could not participate in the case as AG because of his direct role as a Judge. Actually, since he would no longer be a Judge at that point I guess it would be under the ABA Model Rules of Professional Conduct, assuming those are the rules that govern in Federal court. I can't cite the specific section without looking it up, and I'm too lazy to do that. But if you check I bet I'm right.

Exactly, he wouldn't be a judge anymore, so the Rules of Judicial Conduct don't apply.

If he reads this blog/comments, I'd encourage (beg, exhort, cajole, etc) him NOT to take the job. He's far more valuable as a conservative federal judge, with a lifetime appointment, than as the AG for a lame-duck administration with eighteen months left in office.

I looked it up. If the ABA Model Rules apply, rule 1.12(a) would prevent him from representing The District unless all parties to the proceedings give informed consent. This is the Rule of Professional Conduct, not the Rules of Judicial Conduct. But the U.S. Attorney General's office is not representing the District in the Parker case anyway, is it? It is the Attorney General's Office of the District of Columbia. Isn't that like a state AG and not the U.S. AG?

He is a Originalist but still believes
that even wrongly-ruled case law should
remain said case law.