The unanimous ruling denied Mexico’s ridiculously overreaching effort to impose its own vision of gun control within the U.S. by means of a lawsuit.

The second big, unanimous victory at the Supreme Court this morning came in Smith & Wesson Brands v. Estados Unidos Mexicanos, a ridiculously overreaching effort by the Mexican government to impose its own vision of gun control within the United States by means of a lawsuit. As I explained the stakes in October:

The Mexican government filed a massive damages lawsuit alleging that the carnage wrought by heavily armed Mexican drug cartels was the fault not of the cartels or the corrupt and compromised Mexican government, but of legal gun sales in the United States. If successful, the suit would effectively outlaw the AR-15, guns capable of holding more than ten rounds of ammunition, and other legal weapons. The Supreme Court has long been skeptical of similar efforts at end runs around the legislative process and constitutional rights via tort law, especially when undertaken by foreign governments. So has Congress, which enacted the Promotion of Lawful Commerce in Arms Act almost 20 years ago. But the First Circuit concluded that Mexico had alleged that the gun makers “aided and abetted” illegal activities, which “proximately caused” gun deaths in Mexico. That required a lot of bizarre leaps of logic that distorted the statutory definitions of those well-known common-law terms, conflicting with how the Court has read the same terms in other statutory contexts.

The Court traditionally assumes that the proximate-cause standard, being grounded in deeply-embedded principles of Anglo-American common law, is intended by Congress to be incorporated in any federal statute that uses the language of causation unless it quite explicitly creates a different causation standard. Thus there are a great many cases applying the same basic proximate-cause standard under the Racketeer Influenced and Corrupt Organizations Act (RICO) and a host of other federal laws. As I noted on Tuesday regarding a “climate homicide” lawsuit against oil companies, the Court’s oft-quoted standard is that “the general tendency of the law, in regard to damages at least, is not to go beyond the first step.” PLCAA explicitly uses the phrase “proximate cause.” Similarly embedded in numerous federal statutes, as in the Justice Against Sponsors of Terrorism Act of 2016 (JASTA), which was the basis of the Court’s decision in Twitter, Inc. v. Taamneh (2023) (ruling that Twitter wasn’t legally responsible for its platform being used for ISIS recruitment), and likewise expressly incorporated in PLCAA, is the traditional common-law definition of “aiding and abetting.”

So it is here. And Justice Elena Kagan’s opinion for a unanimous Court didn’t even get to the proximate cause question because it concluded that there wasn’t even a plausible allegation of aiding and abetting under the standard laid out by Justice Clarence Thomas’s opinion for the Court in Twitter. It did so even though the case came to the Court on a motion to dismiss the complaint, under which the courts assume that all the facts plausibly alleged by the plaintiff are true and ask only whether those facts, if proven true, would add up to a violation of law (or, in this case, to an exception to PLCAA’s liability shield).

The traditional aiding and abetting standard requires knowing participation and substantial assistance — and importantly, it requires that those things be connected to how the criminal commits the crime — not generally to the criminal or generally to the type of crime. As Kagan noted, without specifics, it’s a very high bar to plead a theory of aiding and abetting out of industry-wide practices rather than assistance to some specific crime:

The complaint does not pinpoint, as most aiding-and-abetting claims do, any specific criminal transactions that the defendants (allegedly) assisted. It does not say, for example, that a given manufacturer aided a given firearms dealer, at a particular time and place, in selling guns to a given Mexican trafficker not legally permitted to buy them under a specified statute. Instead, the complaint levels a more general accusation: that all the manufacturers assist some number of unidentified rogue gun dealers in making a host of firearms sales in violation of various legal bars. The systemic nature of that charge is not necessarily fatal. But . . . it cannot help but heighten Mexico’s burden. . . . To survive, the charge must be backed by plausible allegations of pervasive, systemic, and culpable assistance. . . .

In asserting that the manufacturers intentionally supply guns to bad-apple dealers, Mexico never confronts that the manufacturers do not directly supply any dealers, bad-apple or otherwise. They instead sell firearms to middlemen distributors, whom Mexico has never claimed lack independence. . . . Given that industry structure, Mexico’s complaint must offer some reason to believe that the manufacturers attend to the conduct of individual gun dealers, two levels down. But it does not so much as address that issue. And even assuming the manufacturers know everything the distributors know, the complaint still would not adequately support the charge that they have identified the bad-apple dealers. Mexico does not itself name those dealers. . . . Nor does Mexico provide grounds for thinking that anyone up the supply chain—whether manufacturer or distributor—often acquires that information. Indeed, the complaint points out that government agencies only sporadically provide upstream companies with information tracing Mexican crime guns to certain dealers. . . . So Mexico’s allegation on this score is all speculation; even on a motion to dismiss, it is not enough.

Mexico’s complaint alleges that some, though unidentified, dealers often engage in illegal transactions with Mexican traffickers. . . . The complaint alleges that the manufacturers know that much to be true—that among the whole class of dealers, there are some who routinely violate the law. . . . The complaint alleges, with sufficient plausibility, that the manufacturers could do more than they do to figure out who those rogue dealers are, and then to cut off their supply of guns. . . . But that is to say little more than the plaintiffs said in Twitter. [Quotations and citations omitted.]

That’s not enough, because the law does not make an aider and abettor out of everyone who could have stopped a crime but failed to act:

Mexico’s second set of allegations—that the manufacturers have declined to suitably regulate the dealers’ practices . . . —cannot fill the gap. Of course, responsible manufacturers might well impose constraints on their distribution chains to reduce the possibility of unlawful conduct. . . . So too, those manufacturers might decide, as Mexico urges, to themselves monitor dealers’ sales for law violations. . . . But a failure to do so is, again, what Twitter called “passive nonfeasance”—a failure to stop independent retailers downstream from making unlawful sales. . . . Such omissions and inactions, especially in an already highly regulated industry, are rarely the stuff of aiding-and-abetting liability. . . . Nothing special in Mexico’s allegations makes them so. A manufacturer of goods is not an accomplice to every unaffiliated retailer whom it fails to make follow the law. [Emphasis added; quotations and citations omitted.]

Kagan closed by observing that this was exactly the sort of lawsuit PLCAA was aimed to bar, and that the Court would not let creative lawyering destroy Congress’s handiwork: “Mexico’s suit closely resembles the ones Congress had in mind: It seeks to recover from American firearms manufacturers for the downstream damage Mexican cartel members wreak with their guns. Of course, the law Congress wrote includes the predicate exception, which allows some suits falling within PLCAA’s general ban to proceed. But that exception, if Mexico’s suit fell within it, would swallow most of the rule. We doubt Congress intended to draft such a capacious way out of PLCAA, and in fact it did not.”

Justices Clarence Thomas and Ketanji Brown Jackson each joined the majority but wrote separately to argue for a more expansive reading of the PLCAA litigation bar based on the statute requiring proof that the manufacturer “knowingly violated a State or Federal statute applicable to the sale or marketing of the product.” Jackson argued that Congress meant to allow suits only where the defendant’s conduct broke some specific, democratically enacted law; Thomas contended that it may allow suits only where there was already a judicial finding that the defendant had broken the law.