I recently wrote about the Ninth Circuit's decision in Newsom v. Trump, which ruled that Trump's federalization of the California National Guard last year, was illegal. Previously I assessed the Supreme Court's ruling in the closely related case of Trump v. Illinois. Today, we have a guest post on these and related issues, by Professor Joshua Braver of the University of Wisconsin. Josh is one of the nation's leading experts on the law regulating domestic use of the armed forces, and my coauthor on two article about exclusionary zoning (see here and here).

The Volokh Conspiracy and I are pleased to be able to feature his post on this extraordinarily important issue. It is cross-posted with the Just Security site. What follows below is written by Josh Braver, not me (Ilya Somin):

On October 23, in Newsom v. Trump, the Ninth Circuit struck down President Donald Trump's June 2025 federalization of the National Guard in Los Angeles. Although I agree with the result, I disagree with its reasoning on deference. The issue is whether courts should defer to the president, that is, give a president significant leeway in their assessment of the facts on the ground and whether those facts meet the statutory criteria for deploying the military. The Ninth Circuit decided to be, in its words, "highly deferential" in both its decision on Los Angeles and its decision on federalizing the Guard in Portland. That line of reasoning also influenced the Seventh Circuit's decision to give "great deference" in the Chicago case.

In adopting this "highly deferential" standard, the Ninth Circuit claimed to rely on the statutory history of domestic military deployment. But that history actually cuts in the opposite direction, against deference, as I discuss extensively in an article just published in the Emory Law Journal. The significance of that history extends beyond the recent decision in Newsom, which concerned the novel use of a little-known statute, 10 U.S.C. § 12406. The larger question is whether courts should defer to a president when they invoke the Insurrection Act, the main and most fearsome statute for domestic deployment of the military.

Legal commentators had previously recognized these stakes in the last significant decision on these domestic deployments. After the Supreme Court blocked the deployment of the Guard in Chicago last December, some called the decision a "pyrrhic victory;" as Jack Goldsmith put it, the Insurrection Act still "lie[s] in the wings." In Goldsmith's view, the Insurrection Act is "much more robust" than § 12406, and the "power authorized here is astounding," in large part because of the "greater claim to presidential deference" under the Insurrection Act. According to Goldsmith and co-author Bob Bauer, "The president will receive very significant deference from courts in his determination that an Insurrection Act predicate is satisfied." The Ninth Circuit's decision on deference only adds fuel to that blazing fire of deference for the Insurrection Act. That line of reasoning is, however, not well supported by the statutory history of the Insurrection Act.

Statutory History in Newsom

One of Congress's powers under Article I, Section 8 is to provide for "calling forth" the militia for domestic deployment. The most famous, broadest, and most well-used example of Congress exercising this power is the much-discussed Insurrection Act. But the 2025 deployments in Los Angeles, Portland, and Chicago concerned a heretofore obscure statute, 10 U.S.C. § 12406, which permits federalization of the National Guard in cases of (a) invasion, (b) rebellion, or (c) the president's inability, with the regular forces, to execute the laws of the United States. Newsom v. Trump dealt with the rebellion prong (which Ilya Somin discussed here), while the Supreme Court in Trump v. Illinois addressed the prong involving inability to execute the laws with regular forces.

But there is a specific question of deference. The baseline in statutory interpretation is no deference. Legislatures pass laws and then courts interpret them. When the executive exceeds a statute's authorization as interpreted by the judiciary, courts rule that the action is unlawful. That baseline can be displaced for various reasons. But the most straightforward reason is when the statutory text itself provides for deference, and this was the Ninth Circuit's focus.

Statutes may confer discretion on the president by using subjective terms, such as when a provision turns on what the president "judges," "considers," "deems," "determines," or "finds." For example, in Trump v. Hawaii, the Supreme Court concluded that the statute "exudes deference to the President" because the Immigration and Nationality Act, by its terms, authorizes the president to suspend the entry of aliens whenever he "finds" that their entry would be detrimental to the interests of the United States.  As elaborated in my Emory Law Journal article, the text of the Insurrection Act confers deference in only one of the four conditions for its use, because it sometimes uses the term "considers" and sometimes does not.

In contrast,  there are no subjective discretion-conferring terms in 10 U.S.C. § 12406 that could be construed to confer deference on the president. Both in its recent opinion and in its earlier stay order, the Ninth Circuit acknowledged as much:

"Section 12406 does not include express language making the President the sole judge of whether a required exigency exists. Consequently, if we were considering the text of § 12406 alone, we might conclude that the President's exigency determination is subject to review like certain other factual findings that are preconditions for executive action under a statute."

Nonetheless, the court still decided to be "highly deferential" for two reasons:

"[T]he history of Congress's statutory delegations of its calling forth power and a line of cases interpreting those delegations, beginning with Martin [v. Mott], strongly suggest that our review of the President's determinations in this context is especially deferential."

For the moment, let's leave the court's reliance on Mott to the side, though I will return to it later in the essay. What concerns me here is the Circuit's ostensible reliance on the "history of Congress's statutory delegations." That history, the Ninth Circuit acknowledged, consists largely of the evolution of the Insurrection Act, the principal statute governing domestic military deployments, and the one from which 10 U.S.C. § 12406 descends. For the statutory history of domestic deployments, the court relies solely on the Insurrection Act, but it does not examine that history in much depth. The question is whether those changes in text of the statute over time support deference. They do not.

Statutory History of the Insurrection Act

Today's Insurrection Act has four "triggers," or conditions for domestic deployment. Congress provided express language conferring deference for only one: what I refer to as the judicial-proceedings trigger. There is no deference-conferring language in any of the others.  The statutory history supports this reading of the distribution of deference.  In 1792, the Second Congress rejected deferential language in the first Insurrection Act. Congress would revisit the Insurrection Act two more times: in 1861 and in 1871.  In 1861, it granted deference to the one trigger of judicial proceedings. In 1871, it added two new triggers, but without any deference language.

Let's return to the beginning.  In 1792, Congress considered and rejected deferential language before enacting the first Insurrection Act. The first effort to authorize domestic military deployment came as an amendment to a bill regulating the structure of the state militias. The amendment, passed by the Senate in 1792, authorized the president to call out the militia "as the exigence may, in his opinion, require, to execute the laws of the Union, suppress insurrections, and repel invasions." The crucial words were "in his opinion." Because the president's "opinion" modified every trigger for calling out the militia, the amendment would have given the president substantial deference.

The most vehement opponent of the amendment was Representative William Vans Murray, who condemned the legislation because it meant that "the time, the cause, and the place in which the militia were to be called out should be all left to the discretion of one man." This violated the core principle of the Constitution: "a Government of definition, and not of trust and discretion." Murray's objection prevailed. The House rejected the amendment and directed Murray and two other members to prepare a separate bill. The resulting Calling Forth Act contained no comparable language conferring deference on the president in its triggers.

In 1861, Congress added the phrase "in the judgment of the President" to the provision (language that today is phrased "[w]henever the President considers"), but only to the judicial-proceedings trigger, establishing deference in that trigger but nowhere else. That change was understood to settle the controversy over President Lincoln's use of force against the seceding states at the Civil War's outset. By giving him deference, it overturned James Buchanan's argument that the President lacked such authority under the Insurrection Act to fight the Civil War.  When Congress added two new triggers in 1871, it carried no comparable language, leaving the judicial-proceedings trigger as the sole trigger with deference.  The remaining triggers, including "rebellion" and "invasion" which the Ninth Circuit treats as the antecedents for those terms in 10 U.S.C. 12406, had no deference.

Mott

Martin v. Mott is a much-discussed 1827 Supreme Court decision interpreting the 1795 Calling Forth Act. The Ninth Circuit read Mott as requiring deference to the president. John Dehn and I, among others, believe this misreads the decision, and the court addresses some of those objections. But my concern here is different: how the statutory history casts Mott in a different light and weakens its force as precedent for interpreting either § 12406 or the Insurrection Act to require deference.

First, Mott interpreted an old version of the Insurrection Act statute, the one from 1795. Congress subsequently amended it extensively, including by adding language conferring deference in 1861 but omitting comparable language when it added new triggers in 1871. § 12406's descends from the amended Insurrection Act, and thus its deference must be read in that light.  Second, two of the triggers in today's Insurrection Act were added only in 1871, decades after Mott was decided. Why should Mott's reasoning extend to them at all?

Finally, Mott addressed the invasion trigger, which is no longer part of the Insurrection Act but is now found in a portion of § 12406 not at issue in Newsom v. Trump. Invasion is one of § 12406's three triggers, alongside rebellion and the inability to execute the laws with regular forces. The Ninth Circuit reasoned that if the invasion trigger requires deference, so too must the other triggers under § 12406. I am skeptical.  But even if the Ninth Circuit is right, that is irrelevant to the Insurrection Act because the invasion trigger is no longer grouped with the other triggers in the Insurrection Act.

* * *

The statutory history of the Insurrection Act is extensive, but three developments in 1792, 1861, and 1871 have important implications for deference. Before any court again relies on that history to decide whether, and to what extent, deference is warranted, it must do more than the Ninth Circuit did by merely gesturing at it. It must engage with it. That history, properly understood, casts doubt on granting deference for all but one of the triggers authorizing the president to deploy the military. For the most part, the baseline rule of statutory interpretation remains: Congress has legislated the conditions for domestic deployment, and courts must judge for themselves whether the president has met those conditions without unusual solicitude to a president's views on the matter.

The post Deference, the Insurrection Act, and Statutory History appeared first on Reason Magazine.