Washington, D.C. bans handguns, even when used solely for self-defense. Earlier this year, its gun ban was struck down under the Second Amendment by a federal appeals court --- the D.C. Circuit Court of Appeals -- in Parker v. District of Columbia. Washington is now asking the Supreme Court to review that ruling. Ironically, the law remains in force even after being declared unconstitutional because Washington, D.C., has two parallel court systems that don't hear appeals from each other. The federal courts have declared the ban unconstitutional (in the Parker case), but they will not hear appeals of D.C. municipal court decisions, on habeas petitions or otherwise. By contrast, the D.C. municipal courts upheld that gun ban against a Second Amendment challenge in Sandidge v. United States (1987). And they continue to uphold the ban to this very day, even though the federal appeals court has declared it unconstitutional. This split between the federal courts and the local courts is a classic justification for the Supreme Court to hear this case, so that it can resolve the lingering uncertainty about the gun ban's constitutionality. Earlier, I explained why the Second Amendment does secure an individual right to keep and bear arms. I also explained why it was not judicial activism for the D.C. Circuit to strike down the gun ban, and chronicled the hypocrisy of some critics of the D.C. Circuit's decision, here.