Ted Cruz, a Republican, represents Texas in the Senate.

In 2006, Carol Anne Bond of Lansdale, Pa., burned a woman with caustic chemicals as revenge after the woman became pregnant by Bond’s husband.

Ordinarily, Bond would have been prosecuted for assault, aggravated assault or harassment — in other words, for violating Pennsylvania criminal laws. Instead, federal prosecutors charged Bond with violating the federal legislation implementing the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons. This treaty outlaws the production, collection and use of chemical weapons, including poisonous gases and bacterial weapons, to prevent chemical warfare.

When the U.S. Supreme Court hears oral argument Tuesday in Bond v. United States, the fundamental issues will be U.S. sovereignty and the Constitution’s structural limits on federal power. The questions raised by this case go to the heart of our constitutional system: Does the federal government, through the treaty power, have authority to trump our system of federalism and separation of powers? Does the president’s power to make treaties and Congress’s power to implement treaties have unlimited reach?

The answer to both should be an emphatic no.

The Roberts court has previously ruled to restrict the federal government’s treaty power.

In the 2008 case Medellin v. Texas, which I argued as solicitor general of Texas, the high court upheld U.S. sovereignty and prevented the president from using a treaty to overrule the Texas judicial system. The central questions in that case were: one, could the World Court use a treaty to order American courts to reopen final criminal convictions; and, two, could the president order state courts to submit to the World Court’s authority?

Texas argued that the answer to both questions was no, and the Supreme Court agreed, 6 to 3.

In Bond, the court should again say no to those who would undermine U.S. sovereignty. The treaty power should not trump every other structural protection of our constitutional government.

The U.S. Constitution enumerates powers given to the federal government, and it reserves unenumerated powers to the states and the people. In other words, the Framers created a system of dual sovereignty: the federal government possesses specific powers that allow it to govern over certain subject matters, and the states have authority in areas where the federal government’s powers do not reach. In these separate spheres, either the federal government or the state government is sovereign.

The Constitution does not give the federal government the power to criminalize ordinary assault with ordinary chemicals. That is purely intrastate.

And if treaties can be used to circumvent the Constitution’s enumerated limits on federal power and usurp power given to the states under the Tenth Amendment, the American concept of dual sovereignty would be grievously undermined.

When they consider these points, the justices will surely reflect on this long-disputed sentence from Justice Oliver Wendell Holmes’s 1920 opinion in Missouri v. Holland: “If the treaty is valid, there can be no dispute about the validity of the statute [implementing it] under Article 1, Section 8, as a necessary and proper means to execute the powers of the Government.”

But the broadest reading of that sentence cannot possibly be correct. Could the federal government enter into a treaty that gives Congress the power to ban all political speech? Of course not.

Yet this sentence has been relied upon by the Obama administration and some in the legal academy for the radical proposition that the treaty power can be used to circumvent the structural limits of the federal government.

If the Supreme Court concludes that a treaty can be used to prosecute Americans, regardless of their constitutional rights, the ramifications could be alarming were these treaties to be ratified:

●Nothing would stop the United Nation’s Arms Trade Treaty from being used to vanquish Americans’ Second Amendment right to keep and bear arms.

●Under the Convention on the Law of the Sea, U.S. businesses could be subject to the decisions of the International Tribunal of the Law of the Sea based in Hamburg, Germany, rather than the rulings of American courts.

●The Convention on the Rights of Persons With Disabilities could allow decisions on how to educate a child with disabilities to be made by foreign tribunals rather than by the child’s parents.

Or, consider that state laws favored by liberals, such as California’s environmental laws or a state’s punitive damage laws, could be tossed aside if a conservative president, with Senate approval, crafts a treaty with a foreign country to ban these laws.

It is the province and duty of the Supreme Court to interpret U.S. law. No treaty should abdicate this decision-making power to another authority.

In Medellin v. Texas, the Supreme Court rightly defended U.S. sovereignty and upheld the structural limitations on government power, which serve to protect individual liberty in the United States.

Likewise, in Bond v. United States, the Roberts court should remain faithful to the Constitution and affirm that Bond’s case belongs in Pennsylvania state courts.