On May 15, the Supreme Court will hear oral arguments on the subject of birthright citizenship. If you haven’t been following this controversy, two pieces of information may be helpful.

First, the 14th Amendment, which was ratified in 1868, states, “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

Second, on Jan. 20, President Donald Trump signed an executive order titled “Protecting the Meaning and Value of American Citizenship.” Relying on the words “subject to the jurisdiction thereof,” the order says that certain categories of persons born in the United States are not citizens.

Trump proclaimed that “we are the only country in the world that does this with the birthright.” That is incorrect. More than 30 countries, including Canada and Mexico, grant automatic citizenship to anyone born within their borders.

The order says that “the privilege of United States citizenship” does not belong to a newborn whose mother was either “unlawfully present and the father was not a U.S. citizen or lawful permanent resident,” or whose presence at the time of birth was “lawful but temporary,” and the father was not a citizen or lawful resident.

The word “citizen” is not in the Bill of Rights and appears only sparingly elsewhere in the Constitution – eligibility to run for Congress (Article I, Section 2), the right to vote (15th Amendment) and a few other places. By choosing the word “people” or “person,” both of which appear in the Bill of Rights, and the word “person” in the 14th Amendment, the Founding Fathers and the drafter of the amendment made it clear that fundamental rights in the United States belong to everyone.

Reasonable people could disagree on whether birthright citizenship is a good idea. No reasonable person can maintain, however, that the president has the power to change the Constitution by executive order. Under Article V of the Constitution, amendments can be initiated only by Congress or by constitutional convention and must then be approved by three-fourths of the states.

We have amended the Constitution 27 times. The first 10 amendments, known as the Bill of Rights, were ratified in 1791, four years after the Constitution was signed. Two of the other amendments cancel each other out – the 18th, prohibiting alcoholic beverages, and the 21st, repealing Prohibition. So, in practical terms, 15 operative amendments have been ratified between 1795 and today. The 11th Amendment (1795) deals with federal court jurisdiction; the 27th Amendment (1992) says that no pay raise for members of Congress can become effective until after the next election.

Without going further into the weeds, this brief review reminds us that it is possible to amend the Constitution. It doesn’t happen very often, though not for lack of trying. Over 11,000 amendments have been proposed.

The Constitution serves as the guidebook for American democracy. Some of its provisions state rules that need no interpretation. As one example, Article I, Section 2, provides that “the House of Representatives shall be composed of Members chosen every second year by the People.” We don’t need a court to explain that members of Congress serve two-year terms.

It gets trickier when the Constitution states a principle rather than a rule. The 14th Amendment says that no state may “deprive any person of life, liberty, or property without due process of law” and, further, that all persons are entitled to “equal protection of the law.” Words like “due process” and “equal protection” are not self-explanatory. Under our system, the Supreme Court determines the meaning and establishes the boundaries of those as well as other constitutional principles.

The choice of “person” rather than “citizen” has important consequences. In 1975, Texas passed a law that children of undocumented immigrants could not attend public schools free of charge. In a 1982 decision called Plyler v. Doe, the Supreme Court held that the law violates the equal protection clause of the 14th Amendment. The lawbooks are full of other cases affirming the rights of non-citizens.

In my view, the birthright citizenship clause states a rule, not a principle. The words “subject to the jurisdiction thereof,” as understood in 1868, refer to limited categories, one being children of foreign diplomats, another referring to Native Americans who, until the Indian Citizenship Act of 1924, were considered subject to tribal jurisdiction.

Several federal courts have ruled that Trump’s order is invalid. One judge called it “unavailing and untenable.” Another called the order ”blatantly unconstitutional.”

It’s a good thing the court will soon rule on the question of birthright citizenship. An essential part of our democracy is that we believe in the rule of law. That means that we accept the Supreme Court’s decisions, whether we agree with them or not. If, as I expect, the court rules that Trump’s order is unconstitutional, the president will disagree and likely criticize the justices. Beyond that, however, there isn’t much he can do.

However, more cases are on their way, including whether the government can send undocumented persons to a prison in El Salvador without filing any charges or providing a hearing. Suppose the Supreme Court holds such actions violate those persons’ constitutional rights. Will the Trump administration abide by such a decision or simply ignore it?

The president has sworn to “preserve, protect, and defend the Constitution.” He has no choice but to accept what the Supreme Court decides. Or at least that is what we have always believed. If he refuses to do so, or fails to carry out its directives, then the rule of law will be little more than a memory.

Attorney Joseph D. Steinfield lives in Keene and Jaffrey. He can be reached at joe@joesteinfield.com.