The leaders of the House Oversight and Homeland Security panels on Friday challenged the legality of recent top appointments at the Department of Homeland Security, including newly installed acting secretary, Chad Wolf.

Reps. Bennie Thompson, D-Miss., chairman of the Homeland Security Committee, and Carolyn B. Maloney, D-N.Y., the acting Oversight and Reform Committee chairwoman, have asked the U.S. Comptroller General to conduct an “expedited review” to determine whether the Trump administration acted legally when it appointed both Wolf and his predecessor, Kevin McAleenan, as acting DHS secretary. They also question Wolf naming Ken Cuccinelli to serve as deputy director.

[Suddenly, Ken Cuccinelli is No. 2 at DHS]

Both Democrats support their claim with new documents that show the administration may have violated succession rules when it placed McAleenan next in line after former DHS Secretary Kirstjen Nielsen was pushed out in April, simply because it failed to change them.

If true, that may invalidate McAleenan’s appointment as acting secretary and many actions he took in that role, including changing the rules that eventually allowed Wolf to succeed him.

DHS did not respond to requests for comment Friday.

McAleenan resigned from office Oct. 11. Wolf was named his replacement more than a month later. He was sworn in as acting DHS secretary Wednesday and immediately named Cuccinelli to serve in the agency’s No. 2 position.

But Nielsen’s failure to amend the department’s rules adequately before she left her job “may have rendered Mr. McAleenan’s appointment unlawful from the start,” Maloney and Thompson wrote in their letter Friday. “That would place many of Mr. McAleenan’s decisions in legal jeopardy, including the November 8, 2019 Amendment that was the basis for Mr. Wolf’s appointment.”

[Chad Wolf sworn in as acting DHS chief ]

Nielsen announced her resignation on April 7. She then announced the resignation of Claire Grady, the acting No. 2 at the time, clearing the path for McAleenan, who was actually further down the succession chain.

With their request, the Democrats included an April 10, 2019 copy of the “DHS orders of succession and delegations of authorities for named positions” — rules that determine who would be next in line to head the agency — signed by Nielsen prior to her departure. The document was made public earlier in a Nov. 11 National Journal article.

Nielsen changed the succession order so that McAleenan, who was commissioner of U.S. Customs and Border Protection at the time, would be next, but only in case she is “unable to act during a disaster or catastrophic emergency.” She left the provision determining who would take over in case of her resignation as is, defaulting to a previous executive order that did not put McAleenan next in line.

“In other words, DHS illegally abused the vacancies process because then-Secretary Nielsen messed up the memo that re-did the order of succession to allow for folks who couldn’t otherwise have held those jobs in the first place,” Steve Vladeck, a professor at the University of Texas Law School, wrote on Twitter. “Malevolence tempered by incompetence, exhibit 9532.”

House leaders go even further, arguing DHS violated the succession rules in more than one way in these most recent appointments, likely rendering them invalid. In particular, they note McAleenan’s amendment to the rules of succession was signed Oct. 8, when he was past a 210-day limit for acting officials, per federal vacancies law.

“These maneuvers are a part of a troubling pattern of legal contortions, as well as an end-run around the Senate’s constitutional Advice and Consent power,” the Democratic leaders wrote in their letter. “The Administration has hollowed out the Department leadership, with frequent leadership turnover and abuse of the authority to appoint temporary acting officials. These actions place our nation’s security at risk.”

On Friday, the DHS leadership web page, which as recently as a day earlier had listed Cuccinelli as performing the duties of deputy secretary, showed David Pekoske, the acting head of the Transportation Security Administration in that role.