Carlos Barria / Reuters

President Trump’s announcement on Wednesday that he is nominating his White House physician—Rear Admiral Ronny Jackson—to replace David Shulkin as secretary of veterans affairs has reinvigorated a long-running debate over the proper relationship between the military and the senior echelons of the civil government. Indeed, few modern presidents have surrounded themselves with as many current and former flag officers—including retired General James Mattis as secretary of defense; John Kelly, a retired Marine Corps general, as secretary of homeland security and then White House chief of staff; and H.R. McMaster—a three-star Army general—as the outgoing national-security adviser (who himself succeeded retired Lieutenant General Michael Flynn).

But whatever the policy wisdom of having so many military (and former military) men in senior civilian positions, the Jackson nomination also provides an opportunity to revisit one of the most important—and least understood—statutes with respect to the military’s role in our government: The dual-officeholding ban. Under a statute that dates back to 1870, active-duty officers may not simultaneously hold various “civil offices” (including those that require Senate confirmation) unless Congress has expressly authorized them to do so.

As the Justice Department’s Office of Legal Counsel (OLC) has concluded, the dual-officeholding ban “embodies an important policy designed to maintain civilian control of the Government,” and serves “to bar the appointment of regular military officers to any appointive positions in the civil government, irrespective of the importance of the office, the permanence of the appointment, or the likelihood of interference with the officer’s military duties.” After all, as one of the original sponsors of the bill—Massachusetts Senator Charles Sumner—argued, allowing active-duty military officers to hold such positions would be “in conflict with the fundamental principle of republican institutions,” since it would imply that questions of civilian governance would be resolved, in the first instance, by the military. In that regard, the dual-officeholding ban serves much the same purpose as the Posse Comitatus Act—the 1878 law that bars domestic use of the military for ordinary law enforcement absent express congressional authorization.

As with the Posse Comitatus Act, Congress has carved out a handful of exceptions to the dual-officeholding ban over the course of its history (providing, for example, that the CIA director can be an active-duty officer). But those exceptions prove the rule, and the dual-officeholding ban otherwise continues to “prohibit continuation of [an offending officer’s] military status … upon appointment to a covered position,” as OLC concluded in 2016. That’s why, among other things, Mattis and Kelly had to retire from the military before they could join Trump’s Cabinet. (Congress usually requires an additional seven-year waiting period for secretaries of defense, which it waived in Mattis’s case.) And it’s why, as the White House clarified later on Wednesday, Jackson will also be separating from the Navy before he is confirmed. Otherwise, his confirmation as secretary of veterans affairs would have terminated his military commission. (In contrast, the national-security adviser can be an active-duty officer because that position does not require Senate confirmation.)

But even as the Trump administration has seamlessly and unhesitatingly complied with the dual-officeholding ban with respect to its Cabinet appointments, there is a case pending in the Supreme Court in which the Justice Department is quietly attempting to denude the ban of most of its force—arguing that, even when a military officer is appointed to a civil office in violation of the statute, there’s no legal consequence for the violation. If the Court embraces the government’s position in Dalmazzi v. United States (in which I am counsel of record to the Petitioners), it would not only open the door to far more military officers serving simultaneously in senior civilian positions, but it would fly in the face of what the Court has previously described as “the traditional and strong resistance of Americans to any military intrusion into civilian affairs.”

The specific issue in Dalmazzi, which was argued on January 16, involves the Court of Military Commission Review (CMCR)—an intermediate appeals court that Congress created in 2006 to review cases coming out of the Guantánamo military commissions. The judges on that court are a mix of civilians and active-duty military officers, which has raised the question of whether the latter are serving in violation of the dual-officeholding ban. And because the military judges on the CMCR are also continuing to hear cases in the court-martial system, the defendants in those cases have challenged the judges’ eligibility—arguing that the CMCR appointments voided their military commissions (thereby preventing them from hearing the defendants’ court-martial appeals).

In the Supreme Court, the government has argued that Congress has in fact authorized such dual officeholding. But its alternative argument—and the ground on which the lower courts have relied thus far—is that, even if the CMCR’s military judges are holding two offices in violation of the 1870 statute, federal law does not compel any remedy for the violation. As the extensive briefing in the case suggests, the government’s position isn’t frivolous. But it would also lead to some remarkable results: If this argument prevails, military officers could be appointed to civil offices without facing any mandatory consequences, and so someone like Jackson would not have to resign before accepting a Cabinet position.

Compared to some of the other headline-generating cases the Supreme Court is hearing this term—on the constitutionality of partisan gerrymandering, the travel ban, and public-sector unions, among others—Dalmazzi has largely flown under the radar. But the Jackson nomination helps to underscore the stakes. As a federal appeals court concluded in 1975, the dual-officeholding ban “assure[s] civilian preeminence in government” by “prevent[ing] the military establishment from insinuating itself into the civil branch of government and thereby growing ‘paramount’ to it.” If there really is no remedy for violations of the ban, it is hard to see how the statute could continue to serve that purpose—or stop someone like Trump from filling more and more senior civilian positions throughout the executive branch with active-duty military officers.

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