Supreme Court Lets Michigan Sue Over Oil Pipeline Running Through Great Lakes

April 23, 2026

Dana Nessel Wins Big Against Enbridge on Line 5

Michigan Attorney General Dana Nessel just scored a major win against Enbridge Energy in the U.S. Supreme Court. On April 22nd, the Supreme Court rejected Enbridge's attempt to move a lawsuit over the Line 5 pipeline from Michigan state court to federal court. That might sound like a technical legal victory, but it's actually a huge deal for Michigan's ability to challenge the pipeline project.

The Line 5 pipeline is an oil pipeline that runs through Michigan's Straits of Mackinac, a crucial waterway that connects Lake Huron and Lake Michigan. Enbridge operates it. Michigan says there's a safety risk if it breaks. Enbridge says everything's fine. Michigan wants to shut it down or at minimum oversee its operation. Enbridge wants to keep running it.

Enbridge's strategy was to move the case to federal court, where it figured it would have better odds. The Michigan Attorney General fought to keep it in state court. The Supreme Court just agreed with Michigan, which means the lawsuit will now proceed in Michigan state court under Michigan law.

Why This Matters for Environmental Law and State Power

This is one of those cases where the Supreme Court had to decide: should environmental and safety disputes get handled in federal court (where corporations often have more luck) or state court (where the affected states have more say)? The Court ruled in Michigan's favor, which means states retain the ability to challenge pipeline operations within their borders.

Enbridge made a sophisticated legal argument. They said Congress didn't intend for plaintiffs to use "procedural gamesmanship and lawsuit manipulation to avoid federal jurisdiction." But the Supreme Court basically said: nope, states have the right to protect their waters and their environment, and that right includes the ability to sue in state court.

According to the 9and10 news report of the decision, "The Court rejected Enbridge's counterarguments, including its assertion that a 'clearest command' from Congress is required to rebut the presumption of equitable tolling, noting that prior decisions only required 'good reason' to believe Congress did not intend such tolling."

In English, that means: states don't need an explicit congressional permission to protect themselves; they just need a good reason. And Michigan definitely has a good reason—an oil pipeline running under one of the Great Lakes is pretty significant.

What Happens Now?

The case goes back to Michigan state court. Michigan's lawsuit will proceed there. The question of whether Line 5 can continue operating, or whether it should be shut down, or whether Michigan can impose conditions on its operation, will now be decided by Michigan courts applying Michigan law.

That's a very different outcome for Enbridge than if the case had ended up in federal court. Federal courts are generally more favorable to large corporations and interstate commerce questions. Michigan state courts are more favorable to states' environmental and safety concerns.

Enbridge's business model depends on being able to operate pipelines across state lines. They really wanted this case in federal court. Losing that battle is a significant setback for them.

The Broader Issue: Pipeline Safety and Great Lakes Water

The Line 5 pipeline carries about 23 million gallons of crude oil and other petroleum products daily. It runs under the Straits of Mackinac. If it ruptured, it could cause an environmental catastrophe in the Great Lakes, which supplies drinking water and supports fishing industries across Michigan and surrounding states.

Enbridge says the pipeline is safe, has never had a problem, and shouldn't be shut down. Michigan says the risk is too great and something needs to change. The Supreme Court just said: Michigan, you get to make that argument in your own courts, applying your own laws.

That's actually a pretty significant victory for state power over corporate power.

The Stupid Part

The stupid part is that it took getting all the way to the Supreme Court for this to be resolved. A state should obviously have the right to regulate activities within its borders that could harm its environment and water supply. The fact that this had to be litigated all the way to the Supreme Court shows how much legal infrastructure exists to help corporations avoid environmental oversight.

But Michigan won anyway, which is something.

Sources: 9and10 News (April 22, 2026), USA Today/Dolphins Wire (April 22, 2026), Supreme Court Decision (April 22, 2026)