The oath to uphold the Consititution means that he will go by WHAT IT SAYS. The Constitution says the Congress writes the bills, the presidents signs them into law. The AG is not specifically named in the Constitution as the one person in the land who will decide which laws, passed and unchallenged, shall be enforced and which shall not. It is not a violation of his oath to enforce all the laws passed and unchallenged, though he may personally think them unconstitutional, rather, IT IS HIS JOB.
We do not fix Congressional/presidential errors that way in this country.