Let’s begin with the Constitution, as we must. There are several provisions that may be relevant. There is nothing in Article II ,which sets out the powers of the president, that is directly on point. The most relevant phrase is that the president “shall take care that the laws be faithfully executed,” but that is a very general provision, applicable to federal laws.

Article IV provides that “the United States shall guarantee to every state in this union a Republican form of government, and shall protect each of them against invasion; and on application of the legislature, or of the executive (when the legislature cannot be convened) against domestic violence” (emphasis added). This provision does not specifically empower the president, as distinguished from the United States government in general, to take any action. Moreover, if any action is to be taken, it must be done on application of either the state legislature or the governor. In this case, the president sent federal authorities into states that did not apply for such assistance. So Article IV seems inapplicable.

Article I, which sets out the powers of Congress, not the president, authorizes Congress “to provide for calling for the militia to execute the laws of the union, suppress insurrections and repel invasions.” The demonstrations around the country are certainly not invasions; nor, in my view, are they insurrections. Moreover, Congress has not explicitly authorized the calling out the of the militia in this case.

It is argued, however, that Congress has empowered in, 40 U.S.C. § 1315, the secretary of the Department of Homeland Security to “protect the buildings, grounds and property that are owned, occupied or secured by the federal government,” or any of its agencies. The president may, of course, direct all Cabinet members to ensure that the laws—including this one—are faithfully executed. This would include arresting federal lawbreakers even away from the areas abutting the building themselves. There are other statutes, as well, that grant limited powers, but 40 U.S.C § 1315 is the most relevant.

In sum, therefore, it would seem as if the president does have the power to send in federal authorities to protect federal property even over the objection of state and local authorities, but that statutory power does not seem to extend beyond the protection of federal property and personnel. The president does not have the power to police cities, in general, without legislative or gubernatorial authorization.

Another important question, regarding separation of powers, arises as well. Assuming that the president is acting beyond his authority, do the courts have the constitutional power under Article III to order the president to cease and desist? A related question is who would have standing to raise that issue? If a citizen were hurt by a federal official, perhaps that citizen could raise this issue in a lawsuit. But it is uncertain whether anyone other than an injured plaintiff would have standing to ask the court to order the president to withdraw federal authorities. A federal judge in Oregon ruled that the state attorney general lacked such standing, and other cases are pending.

We are facing unprecedented situations, and it should not be surprising that the law does not provide crystal-clear guidance on the powers of the president in emergency circumstances. Back in the early 1970s, I wrote a series of scholarly articles about the law in times of crisis. After researching cases going back to the Founding of our nation, I summarized the precedents as follows:

It is precisely because the courts will be reluctant to interfere with a president’s actions that the president himself must be sure that his orders are necessary and justified. The Constitution placed great trust in the discretion of the chief executive. Whether this chief executive has lived up to that trust will be judged by the voters.

Alan Dershowitz is the Felix Frankfurter Professor of Law, emeritus at Harvard Law School. Follow him on Twitter: @AlanDersh.

The views expressed in this article are the writer’s own.