Is the DOJ required to oppose the petition? Could they not simply concede that the law is unconstitutional?
The DOJ is not required to oppose the position.
They could put forward a breif stating the ban on short barreled rifles is not Constitutional under the Second Amendment.
They may do so. The Trump administration pushed to remove short barreled rifles from the National Firearms Act, which would kill the registration requirement. The tax has already been removed legislatively, with the law to take effect on January 1, 2026.
Is the DOJ required to oppose the petition? Could they not simply concede that the law is unconstitutional?
~~~~~
Then what will happen when the next liberal president decides that the law IS constitutional, and starts arresting people?
Roberts is attempting to avoid a permanent judgement by this conservative court just so that your scenario can play out without Roberts having to take a stand.