Last month, the U.S. Supreme Court ruled that the District of Columbia had violated the Second Amendment by making armed self-defense in the home impractical and banning the most popular weapons used for that purpose. Last week, the D.C. Council responded by unanimously approving a law that makes armed self-defense in the home impractical and bans the most popular weapons used for that purpose.

D.C.'s political leaders know they are inviting another Second Amendment lawsuit, but they are determined to defy the Supreme Court and the Constitution for as long as possible.

The new law "clarifies that no carry license is required inside the home" to move a gun from one room to another. It also "clarifies" the District's firearm storage requirements, saying a gun may be unlocked and loaded "while it is being used to protect against a reasonably perceived threat of immediate harm to a person" in the home.

Much hinges on what counts as a "reasonably perceived threat." If you're awakened in the middle of the night by a crash, may you carry a loaded gun with you as you investigate? Evidently not. The Washington Post reports that D.C.'s acting attorney general, Peter Nickles, "said residents could neither keep their guns loaded in anticipation of a problem nor search for an intruder on their property." According to Nickles, if you see an armed criminal charging your home, or in the event of "an actual threat by somebody you believe is out to hurt you," you're allowed to get your gun, unlock it and load it.

How long will that take? The new law lets people use a gun safe instead of a trigger lock, which, depending on the type of safe, could allow faster retrieval. But even a gun in a safe has to be kept unloaded, which will tend to slow down the owner's response to a "reasonably perceived threat," assuming he can figure out what that means.

The delay will be even longer because of the District's ridiculously broad ban on "machine guns." The Metropolitan Police Department says the ban covers all handguns except revolvers, which are more cumbersome to load than semiautomatics with detachable magazines.

Under D.C. law, "machine guns" include not only guns that fire continuously but also guns that fire once per trigger pull if they can fire more than 12 rounds without reloading or "can be readily converted" to do so. According to the District's interpretation, even a pistol that fires 12 or fewer rounds counts as a "machine gun" if it could accept a bigger magazine.

That's why Dick Heller, the man who successfully challenged D.C.'s handgun ban, was not allowed to register his seven-shot .45-caliber pistol, which in the District's view might as well be an Uzi. Instead he applied to register a .22-caliber revolver.

Speaking of registration, the District has established a burdensome 12-step process that involves multiple trips to gun dealers and government offices, fingerprinting, a written exam and ballistic testing. How long does all this take? "Up to 14 days," according to one police department publication. "Approximately eight weeks," according to another. "There are circumstances where it could take months," says Police Chief Cathy Lanier.

Registration easily could turn out to be so onerous or capricious that it effectively denies D.C. residents the right to keep and bear arms. The District's revised firearm storage requirements are even more clearly unconstitutional, since they unreasonably interfere with the very function, self-defense in the home, that the Supreme Court said is protected by the Second Amendment. Likewise the arbitrary ban on semiautomatic handguns, the most commonly used self-defense weapons.

"I am pretty confident that the people of the District of Columbia want me to err in the direction of trying to restrict guns," D.C. Mayor Adrian Fenty told Washington Post columnist Marc Fisher. How about erring, just this once, in the direction of respecting civil liberties?