Gun-rights supporters are going to have to come down from their post-Heller high a little earlier than they'd hoped. There's already a considerable amount of legal maneuvering taking place, and for much of it, a bullseye is uncertain.
Most promising are challenges to gun bans nationwide. Since the Supreme Court struck down the capital's ban, it's almost a no-brainer to predict the Court will strike down those in places like Chicago and its suburbs as well.
There's a slight wrinkle when it comes to "incorporation" -- D.C. is a federal enclave, so in Heller the Court didn't have to decide whether the Second Amendment applies to state and local laws as well. However, for the most part, the Bill of Rights has been incorporated (a city council can't limit free speech, even though the First Amendment only restricts "Congress"), and there's no reason to expect anything different to happen when it comes to gun rights.
The wild card lies in what the Supreme Court will determine to be "reasonable" regulation. No right is absolute, and Antonin Scalia's majority Heller opinion explicitly recognized some restrictions as appropriate. For example, bans on felons owning guns, machine-gun regulations, and limits on concealed carry are OK.
IT'S NOT HARD to see how this will get messy in a hurry. The logic in Heller was simple -- the Second Amendment protects American individuals' right to have civilian arms for lawful purposes, so a complete ban on a major type of gun is unconstitutional.
This solved the question at hand quite cleanly, but despite mentioning a few exceptions, the opinion did not create a test for assessing non-ban regulations.
When it comes to the Second Amendment, the Court might end up using one of the "standards of review" it uses for other constitutional questions, or it might come up with a new test. Regardless, the goal will be to balance government safety concerns against the right to keep and bear arms -- the sort of subjective judgment that legislatures are better suited to make.
And since four of the nine judges are already on record as viewing a complete ban as "reasonable," a defection from any of the five judges who ruled with the majority on Heller will probably be enough to uphold any gun-control law. Anti-gunners should see if they can find a particularly wobbly, unprincipled justice among those five (coughKennedycough), and target their appeals to him.
ENTER THE D.C. City Council, which recently passed 90-day "emergency" legislation, and plans to work on (presumably quite similar) permanent legislation in September.
Under the invalidated laws, residents could not register handguns (meaning that almost always, residents could not own handguns), and were required to store long guns in non-functioning states. There was no written exception for self-defense with long guns -- in theory, if a resident experienced a break-in, and took out his legally owned and -stored long gun for protection, he could face penalties.
There are two important aspects to D.C. law today. One comprises the new laws passed to comply with Heller. Two are the laws, old and new, that Heller did not address.
Let's start with the Heller-compliance measures: The city will finally grant handgun permits. It will retain storage requirements, though ("unloaded and either disassembled or bound by a trigger lock...or similar device"), adding a self-defense exception.
In practice, this is a baby step, practically a nose-thumbing at the notion of self-defense. It will give D.C. residents an extra option for defending themselves, the handgun. And D.C. residents rich enough to live in multi-story homes might, in late-night break-ins, have time to put together or remove the trigger locks from, and load, their weapons before the intruders make it upstairs.
Maybe the greater availability of handguns to the law-abiding will deter some crime. But in most cases, a handgun rendered non-functional is a handgun that can't be reached fast enough to address an emergency. This is a powerful case for this measure's unconstitutionality.
BUT WHEN IT comes to the legal details, it's closer to a coin toss. In his opinion, Scalia made an issue of the long-gun law's lack of an exception for self-defense -- if he objected to the storage requirement in itself, he never said so.