If Trump and Pence both get very sick, it's unclear who would be president

It remains unlikely, but hardly unthinkable, that President Donald Trump and Vice President Mike Pence could simultaneously come down with serious cases of COVID-19 — especially after two prominent White House aides recently tested positive for the coronavirus. We have already seen one head of government, British Prime Minister Boris Johnson, incapacitated by COVID-19 and sent to an intensive care unit.

Both men are in high-risk groups: Trump is 73 and overweight; Pence is 60. (Johnson, in contrast, is a comparatively youthful 55.) If they were "ordinary" people, the protocol would be for the two men to place themselves in self-quarantine for two weeks, yet they have not done so.

When Johnson was hospitalized, he deputized his foreign minister to act as prime minister in his absence. Should only the president become ill, then the vice president can take over, following the protocol laid out in the 25th Amendment. But if the vice president becomes incapacitated as well, then we could face a constitutional crisis. It would be triggered by the inadequacies of the Presidential Succession Act passed in 1947 (when there was no vice president, because Harry Truman had succeeded Franklin D. Roosevelt).

Article II of the Constitution grants Congress the right to "provide for the Case of Removal, Death, Resignation or Inability, both of the President and Vice President, declaring what Officer shall then act as President" — and the 1947 act is the current result. Under its rules, the speaker of the House and the president pro tempore of the Senate would be next in the line of succession, followed by the members of the Cabinet, beginning with the secretary of state.

Until 1947, succession had passed through the Cabinet. Congress added the speaker and president pro tem on the grounds that the president should desirably be an elected official, even if not part of the executive branch. This might make sense in theory, but it could be truly terrible in practice. Should both Pence and Trump be unable to serve, Speaker Nancy Pelosi, D.-Calif., would become president under the act — handing the White House to a different party without an election. Should she be unable or unwilling to serve, then the office would go to Sen. Charles Grassley, R-Iowa.

Any effort to transfer power from Trump and Pence to Pelosi would surely inspire legal and political challenges, adding to chaos at precisely the moment the nation desperately needed stability.

To be sure, COVID-19 in the White House could precipitate a crisis well before the Succession Act came into play. It is not difficult to imagine that Trump would deny — and denounce as "fake news" — any suggestion that he lacks the ability, in the words of Article I, Section 2, of the Constitution, "to discharge the Powers and Duties" of the presidency. The vice president and Cabinet can, in theory, overrule him and pronounce him unable to serve, invoking the 25th Amendment. But would they? Even if Pence and the Cabinet displayed independence, would Trump simply fire those who "betrayed" him? He couldn't fire the vice president, but the vice president cannot displace a president on his own; he needs the support of the majority of Cabinet officials — and then Congress.

The act, first of all, bespeaks a simplistic theory of democratic legitimacy that ignores the prominent role that political parties — which have grown far more polarized since 1947 — play in the American system. And it raises vexing legal and practical questions. Most lawyers believe that the speaker would have to resign from the House to serve as president, as a result of the Constitution's obscure incompatibility clause, which says that "no Person holding any Office under the United States, shall be a Member of either House during his Continuance in Office." Perhaps, then, Pelosi would waive her right of succession (since, after all, her "term" would probably last only several weeks at most). So then the 86-year-old Grassley could take on the awesome role of president — should he be willing to resign from the Senate.

There is also a serious argument, first laid out by Yale Law School professor Akhil Reed Amar and his brother, Vikram Amar, now dean of the University of Illinois College of Law, in a 1995 essay in the Stanford Law Review, that the Succession Act is unconstitutional. Article II specifically says that Congress — in setting rules of succession — must select an "officer" as a replacement for the president and vice president. Members of Congress, the argument goes, are not "officers," because they are elected officials and not presidential appointees. (Another legal argument holds that the incompatibility clause does not apply if a member of Congress were to serve as president or vice president, because "officers" refers to people appointed by the president, not to the chief executive position itself. Under that interpretation, Pelosi could retain her legislative office, if the act were upheld as constitutional.)

To put it mildly, it is hard to imagine these questions being litigated in real time should Republicans try to prevent Pelosi from taking office, or should she try to serve as president and speaker simultaneously. This month, Justice Brett M. Kavanaugh evoked the possibility of "chaos" in a Supreme Court argument about "unfaithful electors" — members of the electoral college who opt for candidates besides the ones they pledged to support. The problem of unfaithful electors is trivial compared with the true chaos possible under the Succession Act.

Constitutionality aside, the Succession Act makes little sense as policy: No one seriously believes that the worthies who serve as speaker of the House and president pro tem of the Senate do so because of a belief by the House or Senate that they have the skill set needed to serve as president. Indeed, Grassley occupies his office exclusively because he is the senior member of the majority.

Just as the United States turns out to have been woefully unprepared to confront the coronavirus, so are we unprepared to confront simultaneous presidential and vice-presidential disability. Returning to the pre-1947 rules, under which the secretary of state would follow the vice president in the line of succession, would make far more sense. The Constitution authorizes — is it too much to suggest that it even places a duty on? — Congress to address the possibility that the president and vice president could both become incapacitated. It should face up to its responsibility, before the grim scenario becomes reality.