It certainly is, but nothing in the Supremacy Clause nor anywhere else in the Constitution gives the Supreme Court any authority over anyone other than the actual parties to the cases before it. I will readily grant that Supreme Court rulings are often treated as though they significant authority over other cases, but there's no real legitimate basis for that. If the Supreme Court issues a ruling which agrees with the Constitution and laws, citing such ruling may be a good way to avoid having to re-make the arguments cited therein. On the other hand, if the Court issues a ruling based upon arguments which cannot be reasonably applied to some other case at hand (perhaps because the facts of the extant case don't fit those in the case decided by the SCOTUS, though possibly because the argument was faulty), it would be entirely proper for someone arguing a different case to argue that the Supreme Court precedent does not apply; anyone wishing to claim the precedent as authority should then have to explain why the arguments made thereby are legitimate, and would legitimately apply to the case at hand.
While citing precedent may provide a convenient shorthand for making arguments that were previously made, there should be no "need" to cite precedent except in cases where either the outcome would be genuinely ambiguous without it (meaning either of two contradictory outcomes would both be fully justifiable under the law), or where the effects of an earlier decision may be relevant to a case.
For example, if the court issues a ruling forbidding the enforcement of a particular statute, and someone who is aware of the ruling performs an action which that ruling would seem to declare "legal", the person could legitimately cite the Supreme Court ruling in his defense, without having to defend the legitimacy thereof. Even if the prosecutor could demonstrate that the Court's logic was either faulty or inapplicable to the case at hand, that wouldn't matter if the defendant could show that his conduct was in line with what the Court had said was permissible. I suppose in the latter types of situations, there might be some distinctions between 'enforceable' and 'unenforceable' parts of a ruling, but I would suggest that the main question would be one of what the defendant reasonably believed the Court had said and meant.
Still SCOTUS cases are treated as settled law, even when they are mis-cited (as US v Miller often has been). The few SCOTUS cases that have been over turned have taken years to do so.
This ruling leaves plenty of room for mischief.