DOJ Takes Broad View of Foreign Affairs Preemption in Pipeline Case
October 1, 2025
The Trump Administration has made so many broad assertions of executive power this year that it can be hard to keep track. One such assertion that has not made headlines is found in a statement of interest filed on September 12, 2025, in Enbridge Energy v. Whitmer. At issue is Michigan Governor Gretchen Whitmer’s 2020 decision to revoke the easement for a pipeline across the Straits of Mackinac.
The statement of interest argues that “under the Foreign Affairs Doctrine, the ‘foreign policy of the Executive Branch’ preempts conflicting determinations made in the exercise of state law” (quoting American Insurance Association v. Garamendi (2003)). As I explain below, neither Garamendi nor the Supreme Court’s earlier decision in Zschernig v. Miller (1968) supports the government’s position. Indeed, the executive’s claim of authority to preempt state law is inconsistent with the Supreme Court’s more recent decision in Medellín v. Texas (2008).
A Second Pipeline Case
Enbridge Energy owns a pipeline that runs from Manitoba, through Minnesota, Wisconsin, and Michigan, and then on into Ontario. Recently, the pipeline has generated much litigation. I have previously written about the Wisconsin litigation, in which the Bad River Band of Chippewa Indians sued Enbridge for trespass after the company’s easements through their reservation expired. In that case, Judge William M. Conley ordered the pipeline to shut down by June 2026. Enbridge has appealed that decision to the Seventh Circuit.
A second case relating to this pipeline began in Michigan in 2019. The state’s attorney general sued in Michigan state court to enjoin operation of the pipeline, alleging that it risked a catastrophic oil spill and violated state law. The following year, Governor Whitmer formally revoked Enbridge’s easement across the Straits of Mackinac, and Enbridge sought an injunction in federal court.
Canada filed amicus briefs in both cases, arguing that closing Enbridge’s pipeline violates the Transit Pipelines Treaty between Canada and the United States.
In its own filings, the United States has declined to take a position on the Pipelines Treaty. In the Wisconsin case, the U.S. amicus brief agreed with the district court that Enbridge was trespassing on reservation land but asked the Seventh Circuit to remand so that the district court could reweigh the equities, including the possibility that an arbitral tribunal might find that closing the pipeline would violate the treaty. As I have previously noted, there are good arguments that closing the pipeline would not violate the treaty. And it will be hard for the district court to weigh those arguments without knowing what the State Department thinks.
In its current filing in the Michigan case, the United States still refuses to say what it thinks about the Pipelines Treaty. “The [district court] need not, and indeed should not, interpret or otherwise apply the Treaty,” the statement of interest says, because the court can rule for Enbridge on either of two alternative grounds.
First, the statement argues, the federal Pipeline Safety Act preempts Michigan state law. Second, the statement claims, the so-called “foreign affairs doctrine” preempts Michigan’s action to close the pipeline. I will focus solely on the second argument.
Foreign Affairs Preemption
In Zschernig v. Miller (1968), the Supreme Court struck down an Oregon statute making the rights of noncitizens to inherit property conditional on reciprocal treatment of U.S. citizens in the noncitizen’s home country because the state statute “impair[ed] the effective exercise of the Nation’s foreign policy.” Although the state statute technically regulated probate, the Court concluded that its target was foreign affairs. “As one reads the Oregon decisions,” Justice Douglas wrote for the majority, “it seems that foreign policy attitudes, the freezing or thawing of the ‘cold war,’ and the like are the real desiderata.” In Zschernig, the Court did not defer to the executive, which expressly foreswore any argument that the statute “unduly interferes with the United States’ conduct of foreign relations.”
In the nearly six decades since Zschernig, the Supreme Court has never again invalidated a state statute on grounds of foreign affairs preemption. In Garamendi, the Court discussed Zschernig at some length but rested its decision on the California statute’s conflict with federal policy expressed in executive agreements. Garamendi also suggested that foreign affairs preemption should be limited to cases where a state regulates outside areas of traditional state competence, going on to note “the weakness of [California’s] interest, against the backdrop of traditional state legislative subject matter, in regulating disclosure of European Holocaust-era insurance policies.”
In Medellín, the Supreme Court rejected the executive branch’s claim of authority to override state law by instructing state courts to comply with a decision of the International Court of Justice (ICJ) and reconsider death sentences in cases where a treaty had been violated. The U.N. Charter provision requiring compliance with ICJ decisions was non-self-executing, the Supreme Court reasoned, and the President lacked constitutional authority to enforce it against the states without action by Congress. Nor did Garamendi provide the authority the executive sought. Garamendi, the Court suggested, was limited to cases where the President had settled claims with foreign nations by entering executive agreements. Simply put, Medellín held that the President could not preempt state law just by announcing a policy—the Constitution gives the President authority “to execute the laws, not make them.”
DOJ’s Statement of Interest
The Department of Justice’s filing in Enbridge asserts that the executive branch may preempt state law just by announcing a policy. The statement of interest begins with the uncontroversial propositions that the federal government is supreme in foreign affairs and that the executive branch has the lead role in conducting those affairs. It continues:
Accordingly, under the Foreign Affairs Doctrine, the “foreign policy of the Executive Branch” preempts conflicting determinations made in the execution of state law because the President’s authority over the Nation’s foreign policy is part of the “executive Power” vested in the President by Article II of the Constitution. Am. Ins. Ass’n v. Garamendi, 539 U.S. 396, 413–14 (2003); … To be preempted, a state action need not make the Executive’s foreign policies impossible to effectuate; it is enough that “the likelihood” of the State’s conduct “will produce something more than an incidental effect in conflict with express foreign policy.” Id. at 420.
This broad assertion of authority ignores the limits the Supreme Court has imposed on foreign affairs preemption with respect to both state interests and foreign policy interests.
State Interests
Missing from the executive’s statement of interest is any consideration of whether Michigan is acting within an area of “traditional competence” or “the strength of the state interest,” which the Supreme Court in Garamendi went on to discuss immediately following the last quoted language in the executive’s statement.
Regulating property within the state to protect the environment is unquestionably an area of traditional state competence, and preventing a potentially catastrophic oil spill seems like a strong state interest. Certainly, these interests are stronger than Oregon’s interest in promoting inheritance rights behind the Iron Curtain in Zschernig, or California’s interest in discovering information about insurance policies written in Europe before the Second World War in Garamendi. As in Medellín, the policy asserted by the executive in this case “reaches deep into the heart of the State’s police powers.”
Foreign affairs preemption is a narrow doctrine designed to prevent states from running their own foreign policies. There is no evidence that Michigan is trying to run its own foreign policy in this case. Instead, Michigan appears to have acted just as it would in a purely domestic case, to stop the operation of a pipeline that threatens critical harm to its environment.
Foreign Policy Interests
DOJ’s statement of interest invokes two foreign policy interests. First, “Canada is a key U.S. partner in energy trade, with investment flowing in both directions across the border, and the continued operation of Line 5 plays a significant role in that partnership.” Second, “Michigan’s actions to shut down Line 5 clash with the United States’ foreign policy related to energy and the construction of interstate pipelines, as expressed in recent Executive Orders.”
The Supreme Court’s decisions, however, do not permit invocations such as these to override state law. Garamendi, on which the statement relies almost exclusively, turned on the fact that the federal policy at issue was expressed in an executive agreement. Medellín emphasized this point, reading Garamendi and other cases as limited to “a narrow set of circumstances” involving “executive agreements to settle civil claims between American citizens and foreign governments or foreign nationals.” This case does not fall within Garamendi because the federal policy is not expressed in an executive agreement. Indeed, DOJ’s statement foreswears any reliance on the Pipelines Treaty with Canada, urging the district court not to consider it at all.
In Garamendi, the authority to preempt state law with executive agreements settling claims rested on “a particularly longstanding practice” that “received congressional acquiescence throughout its history.” The difference in Medellínwas the lack of similar practice supporting the assertion of executive authority. The same is true here. Just as there was no longstanding practice of allowing the executive to order state courts to reconsider criminal sentences, so too there is no longstanding practice of allowing the executive to override state decisions regarding easements.
In my view, Medellín forecloses DOJ’s argument. This is not just because Medellín limits Garamendi. It is also because Medellín rejected a similar attempt by the executive to override state law. In order to comply with an ICJ judgment, President Bush issued a Memorandum for the Attorney General stating that the United States would discharge its international obligations by having state courts give effect to that decision. This policy was more specific than the energy partnership with Canada invoked in this case, and no less formal than President Trump’s executive orders relating to energy. If DOJ is correct that its invocations of foreign policy in this case are sufficient to preempt state law, then the Bush Administration should similarly have been able to preempt state law by citing the U.S. partnership with Mexico and its Presidential Memorandum. Yet the Court in Medellín squarely rejected that argument.
Conclusion
Foreign affairs preemption is not a grant of authority to the President to override state law. It is a narrow doctrine, applied only once by the Supreme Court, that allows federal courts to police state efforts to run independent foreign policies. Nothing of that kind appears to be happening here.
Congress has authority to preempt state law with respect to interstate and international pipelines. Enbridge and DOJ argue that the Pipeline Safety Act has done just that, a question that I do not address in this post. But absent a federal statute, preemptive treaty, or executive agreement settling claims, the President lacks authority to override state law. As Medellín emphasized quoting Youngstown, “the President’s power to see that the laws are faithfully executed refutes the idea that he is to be a lawmaker.”