On Friday evening, a federal judge in San Diego blocked enforcement of California's ban on magazines that hold more than 10 rounds, deeming it inconsistent with the Second Amendment right to keep arms for self-defense. U.S. District Judge Roger Benitez concluded that "California's law prohibiting acquisition and possession of magazines able to hold any more than 10 rounds places a severe restriction on the core right of self-defense of the home such that it amounts to a destruction of the right and is unconstitutional under any level of scrutiny." Benitez, who in 2017 issued a stay that prevented the law from taking effect, also agreed with the plaintiffs that the ban amounts to an unconstitutional taking of property without compensation.

In the landmark 2008 case District of Columbia v. Heller, the Supreme Court held that the Second Amendment applies to arms in common use for lawful purposes. Benitez notes that highly popular firearms owned by millions of Americans, such as the Glock 17 pistol, the Ruger 10/22 rifle, and the AR-15 rifle, come equipped with magazines that exceed California's arbitrary limit, which was originally imposed in 2000 and extended to pre-existing hardware by a 2016 ballot initiative. "Millions of ammunition magazines able to hold more than 10 rounds are in common use by law-abiding responsible citizens for lawful uses like self-defense," Benitez writes. "This is enough to decide that a magazine able to hold more than 10 rounds passes the Heller test and is protected by the Second Amendment."

While Benitez thinks that is the appropriate test, he also concludes that California's ban on "large capacity magazines" (LCMs) fails "strict scrutiny," which requires the government to prove that the law is narrowly tailored to achieve a compelling state interest, and even "intermediate scrutiny," which requires that the law be substantially related to an important state interest. The LCM ban "burdens the core of the Second Amendment by criminalizing the acquisition and possession of these magazines that are commonly held by law-abiding citizens for defense of self, home, and state," he writes. "It also fails the strict scrutiny test because the statute is not narrowly tailored—it is not tailored at all. Even under the more forgiving test of intermediate scrutiny, the statute fails because it is not a reasonable fit."

Benitez emphasizes that the avowed aim of the LCM ban—reducing the lethality of mass shootings—is related to a small subset of "extremely rare" crimes: cases where the need to switch magazines creates a "critical pause" during which the perpetrator might be overpowered or his victims might escape. Defensive uses of guns are far more common, and at the beginning of his ruling Benitez describes several cases in which having more than 10 rounds could have made a critical difference. "From the perspective of a victim trying to defend her home and family," he says, "the time required to re-load a pistol after the tenth shot might be called a 'lethal pause,' as it typically takes a victim much longer to re-load (if they can do it at all) than a perpetrator planning an attack. In other words, the re-loading 'pause' the State seeks in hopes of stopping a mass shooter also tends to create an even more dangerous time for every victim who must try to defend herself with a small-capacity magazine."

California reasoned that 10 rounds are plenty for someone firing a gun in self-defense (except, somehow, for active and retired police officers), since the average number of rounds used in such cases is just 2.2. But by the same logic, the state might argue that gun owners do not really need ammunition at all, since firearms are merely brandished in the vast majority of defensive uses. If there are situations where an LCM makes a significant difference in the hands of a mass shooter, there will also be situations where it makes a significant difference in the hands of someone defending himself or others. Benitez suggests a few:

When thousands of people are rioting, as happened in Los Angeles in 1992, or more recently with Antifa members in Berkeley in 2017, a 10-round limit for self-defense is a severe burden. When a group of armed burglars break into a citizen's home at night, and the homeowner in pajamas must choose between using their left hand to grab either a telephone, a flashlight, or an extra 10-round magazine, the burden is severe. When one is far from help in a sparsely populated part of the state, and law enforcement may not be able to respond in a timely manner, the burden of a 10-round limit is severe. When a major earthquake causes power outages, gas and water line ruptures, collapsed bridges and buildings, and chaos, the burden of a 10-round magazine limit is severe. When food distribution channels are disrupted and sustenance becomes scarce while criminals run rampant, the burden of a 10-round magazine limit is severe. Surely, the rights protected by the Second Amendment are not to be trimmed away as unnecessary because today's litigation happens during the best of times. It may be the best of times in Sunnyvale; it may be the worst of times in Bombay Beach or Potrero. California's ban covers the entire state at all times.

Proposition 63, which required heretofore legal owners of pre-2000 LCMs to surrender them, remove them from the state, or sell them to licensed gun dealers, passed in 2016 with support from 63 percent of voters. But constitutional rights are not subject to majority approval. "Constitutional rights stand through time holding fast through the ebb and flow of current controversy," Benitez writes. "Bad political ideas cannot be stopped by criminalizing bad political speech. Crime waves cannot be broken with warrantless searches and unreasonable seizures. Neither can the government response to a few mad men with guns and ammunition be a law that turns millions of responsible, law-abiding people trying to protect themselves into criminals. Yet this is the effect of California's large-capacity magazine law."