DC is a very special place. The States protected their Citizens' right to arms prior to the Constitution. This is as it should be. Whe DC was created, it was by definition new. It had no history, no tradition, no legal inheritance. It was given what the founders gave it, a small piece of land and Congress got exclusive jurisdiction, and I've found conflicting stories about what that means: mainly that Virginia and Maryland shouldn't think they retain jurisdiction over the area they ceded to DC. DC was created like a blank canvas, starting from zero, gun rights never existed for DC residents because there was no tradition of gun rights for the new government. The States inherited theirs, the English Common Law, the Magna Carta, and were powerless to get rid of those even if they wanted. But DC being new, there was no obligation to make it look and feel like a state. Congress was free to experiment. The Constitution BOR simply prevents Congress from interfering with the rights of States and their Citizens. It doesn't grant rights to anyone, nor does it guarantee rights to anyone. It is a negative on what Congress can do to States. For the last of you who will invoke inalienable rights, good luck in DC. DC was created for the express purpose (or may as well have been) of not being encumbered by inalienable rights or anything else that encumbered the States. Congress and its DC don't have to honor any claims to gun rights to those under its jurisdiction. What is alarming is that everyone is under its jurisdiction now.
Before you call me a nut, read 40 Cal 311, People v. De La Guerra. More is on my about page.