In my lifetime, going back to Earl Warren, apparently there has been no real way to ensure that a SCOTUS nominee will perform on the court as expected. One can only choose based upon past performance. Perhaps the Swamp gets to some, but there are others that have not disappointed - e.g. Scalia, Thomas.
The most hopeful sign that he is not another "Deep State Bush Stooge" is that he wasn't appointed by Bush, whom apparently was ALWAYS a Deep Stater.
Abraham Lincoln apparently took your theory to heart and purposely appointed a Deep State elite, Chase, so as to appeal to the better angels of Chase’s nature.