A six year battle between the state of Michigan and a local billionaire will come to a head this November, when voters decide whether to build the first public bridge between Detroit and Windsor, Canada. The ballot initiative will be voted on despite an agreement Michigan Gov. Richard Snyder, a Republican, reached with the Canadian government earlier this year which, Snyder says, can't be overturned by the referendum.

The billionaire, Manuel Maroun, has spent at least $2.19 million bankrolling a nonprofit organization, The People Should Decide, via his company DIBC Holdings. Over the past two years, the ...