The Trump Administration broke the law. That is the conclusion reached by the Government Accountability Office (GAO) following its investigation of the Department of Homeland Security’s (DHS) leadership structure. GAO’s investigation examined whether the current “Acting” Secretary of DHS is illegally serving in violation of the Homeland Security Act of 2002 (HSA), which demands the Senate’s confirmation for high-ranking (PAS) officers in accordance with the Constitution’s Appointment Clause. GAO’s report could ultimately present wide-ranging legal ramifications for the Department.

The controversy begins with the HSA’s mandate that the Secretary of DHS be nominated by the President and appointed with the Senate’s advice and consent. In 2017, Kirstjen Nielsen was nominated by President Donald Trump to serve as DHS Secretary and confirmed by the Senate through this process. But after Secretary Nielsen was reportedly forced to resign her post in April 2019 following disagreements with senior White House officials over the Administration’s controversial family separation policy, President Trump forewent the formal appointment process, instead naming Kevin McAleenan as acting Secretary of DHS.

The Federal Vacancies Reform Act of 1998 (FVRA) authorizes the President to fill vacant PAS positions with acting officials who may serve up to 210-days without the Senate’s confirmation. However, GAO’s report found that since the HSA expressly established a unique line-of-succession, DHS falls outside the FVRA’s exclusivity provision contained in Section 3347(a). Indeed, Secretary Nielsen exercised her power under the HSA in February 2019 to reorder the agency’s succession line. Her delegation designated DHS’s Under Secretary for Management as the first-in-line to succeed as acting Secretary followed by the FEMA Administrator, the Director of the Cybersecurity and Infrastructure Security Agency (CISA), and the Under Secretary of Science and Technology, respectively. This succession line was to take effect upon Nielsen’s “death, resignation, or inability to perform the functions of the office,” and only permitted an officer to assume the duties of acting Secretary had he or she received Senate confirmation for their current post.

However, the day before Secretary Nielsen resigned, she again amended the succession order. The succession line Nielsen amended was to take effect only in the event of her unavailability during a “disaster or catastrophic emergency,” thus creating a separate succession order while keeping her February delegation intact. Regardless, under both succession lines, Mr. McAleenan—who served as the Customs and Border Patrol (CBP) Commissioner at the time—was not first-in-line to serve as DHS’s acting Secretary. While Nielsen’s February delegation did not even list the CBP Commissioner, her subsequent delegation placed McAleenan third-in-line behind the Deputy Secretary and Under Secretary for Management.

To work around this inconvenience, the Trump Administration left the Deputy Secretary office vacant while forcing the Under Secretary to resign. Nevertheless, the Under Secretary’s forced resignation still did not change the fact that McAleenan could legally only take office in the event of Nielsen’s unavailability during an emergency. Rather, according to GAO, because there was no emergency and both the Secretary and Under Secretary positions remained vacant and because the FEMA Administrator lacked Senate confirmation at the time, the Director of CISA should have assumed the acting Secretary role.

Somehow, this is only the tip of GAO’s investigative iceberg. Following his appointment, Mr. McAleenan used his questioned authority to once again amend DHS’s succession line and then abruptly resigned his posts as acting Secretary and CBP Commissioner one week later. Continued vacancies in the Deputy Secretary and Under Secretary positions meant that the acting Secretary role under McAleenan’s suspect delegation fell to Chad Wolf, who had received the Senate’s confirmation to serve as Under Secretary for Strategy, Policy, and Plans only days earlier. Upon assuming office, Mr. Wolf quickly issued his own reordering of the Department’s line-of-succession that allowed Ken Cuccinelli, the Principal Deputy Director of Citizenship and Immigration Services (USCIS), to perform the Deputy Secretary’s duties.

However, McAleenan and Wolf’s reshuffling of DHS’s leadership may be moot. GAO’s report asserts that since Mr. McAleenan was not legally permitted to assume the role of acting Secretary under the plain language of Secretary Nielsen’s February delegation, his subsequent reordering of the Department’s succession line was also invalid. Thus, GAO concluded that Mr. Wolf and Mr. Cuccinelli are both serving in their posts unconstitutionally.

Ultimately, GAO’s report is indicative of a broader trend of concern within the Trump Administration. President Trump, claiming his preference for the “flexibility” acting officials give him, has relied upon acting officers in leadership roles more than any other administration in modern history. Indeed, a report in February estimated that acting officers have served at least 2,700 days combined in cabinet-level positions during the Trump Administration, and this estimate does not account for the various acting PAS officers at administrative agencies or PAS offices whose duties have been delegated to inferior officers but remain vacant. This preponderance of acting officials and the Administration’s circumvention of the Senate’s confirmation process inherently weakens Congress’s oversight power. Congress could reign in a president’s unilateral appointment of PAS officers if it amended agency statutes and the Vacancies Act. This would help ensure that both agency independence and congressional oversight remain intact. No matter who is in the White House come January 20, Congress should seek to re-establish its constitutional authority to shape and regulate the executive branch.