WHEN President Donald Trump tapped Matthew Whitaker to become acting attorney-general following Jeff Sessions’s departure from the Justice Department (DOJ) on November 7th, legal experts were divided on the legality of the move. Some argued that Mr Whitaker’s appointment violated Article 2, section 2 of the constitution, which requires the advice and consent of the Senate before top-level advisors are seated. Others pointed to a Supreme Court decision from 1898 permitting individuals who have not been confirmed by the Senate to serve as principal officers “for a limited time, and under special and temporary conditions”. The DOJ insisted the temporary appointment is in accord with the constitution and with a law from 1998, the Federal Vacancies Reform Act.

As debate swirls in op-ed pages, litigants opposed to Mr Whitaker’s promotion to the top law-enforcement position are turning to the courts. At least four legal challenges have sprung up. The first came in Maryland on November 13th, where Brian Frosh, the state attorney general—in a case regarding the DOJ’s handling of Obamacare—moved to replace Mr Whitaker with Rod Rosenstein, the deputy attorney-general who was confirmed by the Senate in April 2017. Thomas Goldstein, a Washington lawyer who frequently argues cases at the Supreme Court, shepherded both Maryland’s motion and a novel gambit on November 16th that may spur America’s highest court to address the legality of Mr Whitaker’s appointment on an expedited schedule.

The request to the justices comes in the guise of Michaels v Sessions, a case challenging the federal ban on guns for convicted felons that has seen its caption change to Michaels v Whitaker. Michaels is still at the petition stage; the justices will consider in January whether to accept it onto their docket. But Mr Goldstein is seeking to press the question of the rightful acting-attorney general in advance of that determination. The motion notes that tarrying carries significant costs. “If this court declines to resolve this question immediately”, Mr Goldstein wrote, and instead invalidates Mr Whitaker’s appointment several months on, the “unwinding” of orders issued in the interim “would be a fraught and disruptive exercise that could embroil the federal courts” in countless disputes. Permitting the administration to select which law it likes when tapping an official entails a “Schrödinger’s acting attorneys-general” conundrum—two individuals tasked with leading the DOJ at the same time. That, Mr Goldstein wrote, “is not how America works”.

Another challenge to Mr Whitaker’s authority is pending in St Louis, where William Douglas Haning, a Texas businessman, faces criminal charges for using low-quality ingredients in pet food. Mr Sessions happened to have taken a direct role in Mr Haning’s prosecution, so the substitution of the former attorney-general’s name with that of Mr Whitaker gives lawyers a clean target for testing the constitutional argument that Mr Trump illegitimately inserted him into the role. According to Stephen Vladeck, a law professor at the University of Texas, this case “is a good example of a context in which Mr Whitaker actually has to play an ongoing role” and may give opponents of Mr Trump’s pick an ideal opportunity to fight his installation.

The latest salvo against Mr Whitaker was launched by three Democratic senators on November 19th. Richard Blumenthal, Mazie Hirono and Sheldon Whitehouse filed a complaint at the federal district court for the District of Columbia contending that Mr Trump’s appointee cannot assume his position without the assent of a Senate majority. Turning to Federalist no. 76, the senators’ lawyers at the Constitutional Accountability Centre and the Protect Democracy Project, legal advocacy organisations, cited Alexander Hamilton’s warning against presidential appointees who have “no other merit than that of…possessing the necessary insignificance and pliancy to render them the obsequious instruments of his pleasure”. The advice-and-consent rule exists, Mr Hamilton wrote in 1788, to secure top federal officers who are inclined toward the public good rather than the president’s “private inclinations and interests”.

Mr Blumenthal said that anyone who has seen Schoolhouse Rock, the video civics primers for children, would recognise the “flagrant constitutional violation” in Mr Whitaker’s appointment. Given that Mr Trump’s named acting attorney-general “has been a vocal and frequent critic of the Mueller investigation”, the complaint says, the Senate must look carefully at his record before permitting him to head the DOJ. The Senate’s constitutional duty to provide advice and consent to presidents in their selection of cabinet-level advisors and agency heads will be impossible to carry out, Mr Blumenthal argued, if Mr Trump’s “end run” is permitted to stand.

The senators must clear a hurdle before the DC court considers the substance of this challenge: the requirement that parties show a clear injury from Mr Whitaker’s appointment. Citing a Supreme Court case from 1997, the senators’ complaint argues that “[u]nlawfully denying legislators their right to cast an effective vote robs them of one of their core powers and responsibilities”. That claim may be harder to establish, Mr Vladeck says, where the litigants are a trio of individual senators rather than a committee or the full Senate. But the lawmakers note that a Supreme Court case from 2015 involving the Arizona legislature gives them further support and that the judiciary is the only forum where their constitutional powers might be vindicated.