The outdated, 68-year-old pipeline in the Straits of Mackinac is set to be shut down in May. Enbridge's time has run out -- but they aren't going down without a fight. A Line 5 rupture in the Straits of Mackinac would impact 700 miles of Great Lakes shoreline, take years to clean up and devastate our Great Lakes economy. Shutting down Line 5 is crucial to protect the Great Lakes from a catastrophic oil spill. Join Michigan LCV and Jeff…