A recent ruling has sparked significant interest and concern, as a federal judge has ruled that Michigan does not have the authority to shut down the Line 5 pipeline, which runs through the Straits of Mackinac. This decision, made by Judge Robert J. Jonker on December 17, 2025, in U.S. District Court in Lansing, favors Canadian oil transportation company Enbridge, effectively blocking Governor Gretchen Whitmer from enforcing a 2020 directive aimed at revoking Enbridge's easement from 1953 that permits the operation of these twin pipelines.
Judge Jonker affirmed Enbridge's argument that the governor's shutdown order breaches the Supremacy Clause of the U.S. Constitution. This clause establishes that federal laws take precedence over conflicting state legislation. Given that interstate pipelines are governed by the federal Pipeline Safety Act of 1992, Jonker deemed Whitmer's actions inappropriate.
Additionally, the judge concurred with Enbridge's assertion that the state's move to halt operations interferes with federal management of foreign affairs, particularly regarding the transport of hydrocarbons as stipulated in a treaty established in 1977. Notably, both the Canadian government and the Trump Administration have expressed support for Enbridge during these proceedings.
Line 5 is a critical infrastructure component that transports an astonishing 23 million gallons of oil and natural gas liquids each day. It traverses the Upper Peninsula, splitting into two underwater pipelines through the Straits of Mackinac—pipelines that are now 72 years old—before merging into a single line heading south toward Sarnia, Ontario.
Enbridge has a controversial history, having been implicated in one of the largest inland oil spills in U.S. history. In July 2010, a major leak from one of its transmission lines near Marshall, Michigan, contaminated over 38 miles of the Kalamazoo River, leading to a cleanup effort that spanned four years and cost over $1 billion. In 2016, the company settled with the U.S. Justice Department and Environmental Protection Agency for $177 million related to this incident and another spill in Romeoville, Illinois, which included $62 million in penalties.
Critics warn that a similar disaster involving Line 5 could have catastrophic consequences for communities along the Great Lakes shoreline and would severely impact Michigan’s economy. Conversely, Enbridge maintains that the safety of Line 5 is assured, and they are currently pursuing permits to construct a new tunnel beneath the Straits, which they claim would enhance safety by housing a replacement pipeline.
In November 2020, Governor Whitmer formally announced her intention to cancel the easement allowing Enbridge to operate the pipelines, citing ongoing and serious violations of the easement’s terms. Among the issues identified were damage from anchor strikes, missing supports, and deterioration of protective coatings.
Whitmer expressed her deep concern, stating, "Enbridge has routinely refused to take action to protect our Great Lakes and the millions of Americans who rely on them for clean drinking water and employment opportunities. They have repeatedly disregarded the terms of the 1953 easement, ignoring structural deficiencies that pose risks to our Great Lakes and families. Most importantly, Enbridge has placed an unacceptable risk of a catastrophic oil spill in the Great Lakes upon the people of Michigan that could devastate our economy and way of life. That’s why we’re taking action now, and I will continue to hold accountable anyone who threatens our Great Lakes and freshwater."
In his judgment, Judge Jonker did acknowledge the significant risks associated with the ongoing operation of Line 5. He remarked, "An oil spill in Michigan's Great Lakes would undoubtedly lead to an environmental disaster, and Michigan would bear the brunt of the resulting damage."
He also highlighted the importance of protecting the Great Lakes, which harbor approximately 84% of North America's fresh surface water and about 21% of the world's total supply. "They must be safeguarded," he emphasized.
Jonker emphasized that all relevant parties—Enbridge, the United States, and Canada—should collaborate to ensure the protection of the Great Lakes. However, he noted that the national government has clearly opted to assert federal control over state power in this domain, thus assuming exclusive responsibility for the safety of interstate pipelines. He stated, "It is not the role of this Court to assess the wisdom of the national government's policy."
By granting Enbridge's motion for summary judgment, Judge Jonker effectively bypassed the need for a trial based on the established facts. He also dismissed the state’s request to delay or abstain from his ruling to allow for another case between Michigan's Attorney General Dana Nessel and Enbridge to proceed in state court, citing the clear federal supremacy regarding the matters raised by Line 5.
Danny Wimmer, the press secretary for Nessel's office, indicated that they are currently reviewing the judge's opinion with the governor’s team to determine potential next steps, which may include appealing this decision. "From our preliminary analysis, this ruling appears to misinterpret the law and undermines Michigan’s sovereign rights regarding the management of its submerged lands," he explained.
Meanwhile, the Attorney General's lawsuit, known as Nessel v. Enbridge, is still ongoing in the Ingham County Circuit Court.
