This commentary originally appeared in Real Clear World on August 4, 2015.

In the wake of the Supreme Court's federal-power-promoting rulings in Burwell and Obergefell, a new mood may be surfacing among opponents of federal overreach: angry refusal to cooperate further with a federal government deemed lawless. This mood swing has been long in coming. A recent Rasmussen poll finds that 55 percent of voters "have long believed that the Supreme Court justices have their own political agenda." In the weeks following the Court's controversial June rulings, Rasmussen finds strong upward movement in the number of Americans who agree that "states should have the right to ignore federal court rulings if their elected officials disagree with them." When asked this question in February, 24 percent of respondents agreed. Now, that percentage has climbed to 33 percent.

Does this represent a trend or merely a momentary blip in the country's sentiments? The rising national debate over President Obama's Iran agreement may provide the answer. The president, endeavoring to go around Congress, decided not to categorize the agreement to limit Iran's nuclear capacity as a treaty, which would require ratification by the U.S. Senate. Instead, the "executive agreement" to end international sanctions against Iran has been submitted by the White House to the full Congress for approval under the 60-day timetable provided for by the Corker-Cardin Act. The political calculation behind the president's move is this: Were the Iran agreement submitted as a treaty, the Constitution requires approval by two-thirds of the Senate-a tall order under normal circumstances, but especially difficult, if not impossible, given the current climate. But, under the terms governing executive agreements, if Congress votes to reject one or more of its sanctions-lifting provisions, the president has already declared that he will exercise his veto power. To uphold his veto, he needs only to recruit one-third of both bodies' members, because it takes a two-thirds vote of both houses to override a presidential veto.

But the president's effort to escape the judgment constitutionally provided to the U.S. Senate may have placed the fate of his Iran deal in the hands of the states, which have few constitutional opportunities to meaningfully affect foreign policy. How? In 2008, U.S. Senator Ted Cruz (R-TX) was Texas Solicitor General, in which capacity he defended Texas successfully in the U.S. Supreme Court case,Medellin v. Texas. In this case, the Court ruled that international agreements to which the United States is a party do not automatically bind the states unless Congress passes laws implementing the agreement. At this date, Congress has passed no such laws, and it is unlikely that the needed majority in both houses exists.

In light of Medellin, a number of critics of the Iran deal have issued a call to arms to states, counseling them that they have the power to resist it. Specifically, they cite two passages from the Iran agreement. Section 25 states, "The United States will actively encourage officials at the state or local level to take into account the changes in the U.S. policy reflected in the lifting of sanctions" under the deal, "and to refrain from actions inconsistent with this change in policy." Section 37 of the agreement stipulates, "Iran has stated that if sanctions are reinstated in whole or in part, Iran will treat that as grounds to cease performing its commitments" under the deal. Simply put, the U.S. pledges to bring the states along in the deal; in response, Iran replies that, if this doesn't happen, the deal is off.

For critics, these two passages form the matrix out of which could arise a substantive federal-state conflict and, with it, the demise of the Iran agreement. Monday, two constitutional lawyers, David Rivkin and Lee Casey, wrote that the Iran deal is "unconstitutional, violates international law and features commitments that President Obama could not lawfully make." But, they add, states can "derail" this "end-run around the Constitution" through "enacting their own Iran sanctions legislation."

Had President Obama sought and won approval of the Iran agreement as a treaty, it would have been binding on all the states. However, his chosen "executive-agreement approach," argue Rivkin and Casey, "cannot pre-empt the authority of the states," leaving them constitutionally free to "impose their own Iran-related sanctions, as they have done in the past against South Africa and Burma." 

In fact, thirty states have anti-Iran divestment laws on their books today. And, as some analysts have observed, support for such legislation transcends the red state-blue state divide. Blue California and New York, for example, have passed strong divestment legislation. If these and/or other states take up the charge and continue economic sanctions against Iranian companies or the Iranian regime, then, under Section 37 of the joint agreement, Iran could be expected to withdraw from the pact.

If both of these events actually occur down the line-states continue to impose sanctions and Iran therefore aborts the deal-some will doubtless proclaim the political irony that a presidential scheme intent on avoiding the Senate's constitutional prerogatives only served to open the door through which the individual states themselves defeated the president's intentions.

But this is not mere irony. It is the proper operation of the rule of law under our Constitution. Despite the attitudes and actions of the current White House and five members of the Supreme Court, the Congress, under our system of representative democracy, necessarily predominates over the other branches. For this reason, the Supreme Court rightly ruled in Medellin that even treaties-and therefore "executive agreements," which are weaker than treaties-cannot be imposed on states absent explicit legislation from the national legislature. What the Court in Medellin reads the Constitution to intend is that, in the vital matters that international agreements often touch, the federal branch of government closest to the people, the Congress, must act before states and their citizens can be lawfully ordered to obey.

The Framers of the Constitution knew well the tendency of officeholders to attempt to encroach on the rights of the other branches. They attempted to provide safeguards for this eventuality through the constitutional separation of powers in the federal government and the Tenth Amendment, which leaves to the states all powers not granted to the federal government. By correctly interpreting the Framers' intentions in Medellin, the Court may have paved the way for a powerful demonstration that an "end-run around the Constitution" may not be quite as easy as it appears. If that occurs, not only could a deal some deem unconstitutional fail, but also, and equally important, the states will have taken a first, indispensable step toward restoring constitutional federalism.