Somebody else observed (don’t recall where) recently that the bulk of a SCOTUS verdict is basically dicta, explaining why they come to the conclusion they do; interesting as this is, it’s not the absolutely legally binding part. It’s the “Holdings” (or “Held”) part that is the binding core of the verdict, and the pinnacle thereof is the word “affirmed” (or “vacated & remanded”); we can nit-pick the rest, but the final word is in the “holdings”.
If I understand it correctly, "dicta" is anything said in the decision that is not directly relevant to making the specific decision made. Comments in Heller regarding registration, felons, and even "bearing arms" aren't relevant to that part of the scope of the Second Amendment which applies to Heller.
What is less clear to me is whether the Heller decision renders much of Parker to be dicta. Since any level of scrutiny protects Heller's expressed interests, is the decision in Parker regarding "strict scrutiny" simply dicta, now that the Supreme Court has affirmed the lower court, using different reasoning to reach their decision?
Even if much of Parker is now dicta, DC runs a serious risk by flouting the Supreme Court's decision. It seems to me that the DC Circuit Court could, as a result of misbehavior by DC, rule that any ordinances must be approved by that court prior to passing. That would put the DC Circuit Court in the position of enforcing not just Heller, but the Second Amendment as ruled in Parker. That court would not find itself obligated to approve unConstitutional legislation.