One word. Wrong. Nonacquiescence is when an administrative agency to not follow a court ruling when there are subsequent and similar cases to maintain consistency. This was a president and the federal courts have consistently ruled that a president may not suspend habeas corpus - particularly when the courts are functioning.
Oh, he didn’t ignore the Court. The “Court” never even heard the case. It was only Taney!
Oh, yes he did ignore the federal courts. Taney was a SCOTUS judge riding circuit as was the practice in those days.
You need to discover what “ex parts” means. And the order Taney issued (ex parte) was not issued to Lincoln, it was issued to the Commanding officer at Fort McHenry where Merryman was being held. So in actuality it was that Army officer who told Taney to shove his order where the Confederate sun don’t shine, not Lincoln. ;~))