President Trump on his way to board Air Force One in Morristown, N.J., on Sunday. He had spent the weekend at his Bedminster Golf Club. (Kevin Lamarque/Reuters)
John Rogan is a visiting clinical professor at Fordham Law School. He has co-taught a clinic on presidential succession.

Jim Mattis quit as defense secretary in December, Kristjen Nielsen quit as homeland security secretary in April, and Alex Acosta quit as labor secretary this month. Acting secretaries fill all three posts, and if President Trump makes good on hints that Wilbur Ross is not long for his job, there will soon be an acting commerce secretary, too.

I like ‘acting,’ ” Trump said in February. “It gives me more flexibility.”

That is one benefit to the president. Here’s another: It could deter any effort to deploy the 25th Amendment to remove him from the powers of the presidency, even if the vice president and a majority of the Cabinet wanted to.

To be clear, the 25th Amendment has not been a plausible option for ousting Trump, but the subject has come up: Last fall, an anonymous “senior administration official” wrote in the New York Times that “given the instability many witnessed, there were early whispers within the cabinet of invoking the 25th Amendment,” and in February, former deputy FBI director Andrew McCabe said former deputy attorney general Rod J. Rosenstein had brought up the subject briefly after the president fired FBI Director James B. Comey. Those moments were fleeting, and impeachment talk has all but drowned out talk of the 25th Amendment. Even if it had not, there is no evidence Trump is attempting to prevent the amendment’s use.

Still, his Constitution-bending behavior does highlight collateral dangers of failing to adhere to the spirit of a constitutional command — in this case, the requirement that Cabinet secretaries receive Senate confirmation. The 25th Amendment gives Cabinet secretaries critical roles in declaring a president unable to perform his duties, but is ambiguous on whether acting secretaries, who are not confirmed by the Senate to lead agencies, can participate. Critically, that ambiguity could lead to questions about who was legitimately president — exactly a scenario the amendment was meant to prevent.

As many of Trump’s critics have learned since 2016, Section 4 of the 25th Amendment empowers the vice president and a majority of the “principal officers of the executive departments” to remove an “unable” president from the office’s powers and duties. Members of Congress who worked on the amendment said they intended the “principal officers” to be the leaders of the “executive departments” listed in a federal law. Officials holding positions a president might designate as “Cabinet-level,” such as the United Nations ambassador or director of national intelligence, were excluded.

There are 15 executive departments identified in the statute, three of which are led by acting secretaries. Overall, nine Senate-confirmed executive department heads have left their positions during the Trump administration’s first 2½ years — matching the total number of departures in the first terms of the past three presidencies combined (three for Obama, two for Bush and four for Clinton). In some cases, there have been long periods after the departures before Trump nominated replacements — although last week Trump said he intended to name Eugene Scalia, son of the late Supreme Court Justice Antonin Scalia, as labor secretary.

Trump may enjoy the “flexibility” that acting secretaries provide, but it was that very flexibility that the Constitution’s framers wanted to limit. That is why Article II requires the president to appoint secretaries with “Advice and Consent of the Senate.” In addition to reducing accountability to Congress, disregard for this requirement could short-circuit the 25th Amendment’s Section 4.

During the amendment’s drafting in the mid-1960s — after the assassination of John F. Kennedy made clear that presidential succession procedures needed to be clearer — key lawmakers took different positions on whether acting secretaries could take part in the Section 4 process. The House Judiciary Committee issued a report stating acting secretaries could participate, and Sen. Robert F. Kennedy (D-N.Y.) echoed that interpretation. But Sen. Birch Bayh (D-Ind.), the amendment’s principal sponsor, voiced the opposite view. Fordham University law professor John D. Feerick, who helped draft the 25th Amendment, states in his authoritative book on the amendment that the balance of the legislative history indicates acting secretaries are eligible participants.

Nevertheless, the ambiguity took hold in important places. Most significantly, it was noted in contingency plans for invoking the amendment that the White House Counsel’s Office created. The plans were issued during the Reagan administration and passed on through at least George W. Bush’s presidency. The Justice Department’s Office of Legal Counsel, in a memo written days after the 1981 Reagan assassination attempt, also acknowledged the acting-secretary ambiguity.

This lack of clarity would be a serious hurdle to invoking the amendment where an emergency required it, especially if acting officials were positioned to play a decisive role. An action as consequential as removing the president from his powers and duties needs a rock-solid legal basis, given that the legitimacy of the presidency could be at stake.

A president firing Cabinet secretaries and leaving acting secretaries in their place to hinder the amendment’s invocation is unlikely. But it is not inconceivable. One hundred years ago this fall, President Woodrow Wilson had a stroke and disappeared from public view for most of the remaining 18 months of his term. Among his few official actions: firing the secretary of state for calling Cabinet meetings where they discussed the vice president’s taking over.

The most practical way to address the acting-secretaries problem is for presidents, vice presidents and their top aides to commit their interpretation of the issue to writing at the outset of their terms. Such planning would not be unprecedented. At the start of President George H.W. Bush’s administration, he convened an Oval Office meeting to discuss when and how to use the amendment. It is not publicly known whether other presidents have personally engaged in similar planning or whether any, including Bush, clarified the acting-secretaries question.

Such a remedy might not be legally binding, but the 25th Amendment’s framers recognized that laws and procedures come with major limitations. One of the architects, Eisenhower’s attorney general, Herbert Brownell, observed, “No mechanical or procedural solution will provide a complete answer if one assumes hypothetical cases in which most of the parties are rogues and in which no popular sense of constitutional propriety exists.” To work as intended, the 25th Amendment depends on officials acting in good faith and following the letter and spirit of the Constitution’s design.