Michigan’s highest court has yanked Enbridge’s Line 5 pipeline back into the legal spotlight, agreeing Friday to hear Tribal Nations and environmental groups who say the state’s Public Service Commission broke the law when it signed off on a tunnel beneath the Straits of Mackinac. At stake is more than just a construction permit—it’s the future of a pipeline that daily moves nearly 540,000 barrels of crude oil and natural gas liquids (NGLs) through the heart of the Great Lakes. Line 5 begins at Superior, Wisconsin,…