Notice how POTUS worded these tweets? They are implying he meant it sarcastically, but it could also be read as a compliment to Sessions for doing his job regardless of the political situation that it creates. It's all in how one wishes to perceive the tweet.
Two long running, Obama era, investigations of two very popular Republican Congressmen were brought to a well publicized charge, just ahead of the Mid-Terms, by the Jeff Sessions Justice Department. Two easy wins now in doubt because there is not enough time. Good job Jeff………The Democrats, none of whom voted for Jeff Sessions, must love him now. Same thing with Lyin’ James Comey. The Dems all hated him, wanted him out, thought he was disgusting - UNTIL I FIRED HIM! Immediately he became a wonderful man, a saint like figure in fact. Really sick!