Why would Trump want to give the Democrats ammunition for an impeachment? They'd impeach him claiming he fired Sessions because he wouldn't stop the Muller witch hunt. If the witch hunt ever ends and Republicans retain the Senate Trump would have an opening to fire Sessions provided Republican Senators would back him up and approve a replacement. Sessions has allies and buddies in the Senate. Trump has no reason to piss them off at this point. I think he should fire Rosenstein but it's the same deal, Sessions say's he'd resign if Trump fires Rosenstein. I think the bastards in the Justice Department all have something on each other. I think that's how they got Sessions to recuse himself. They know a skeleton in Session's closet.
Just sayin, just supposen! I have no evidence, just suspicions.