Union officials are campaigning to lock collective bargaining rights into Michigan’s state constitution on Election Day and are talking about repeating the feat elsewhere if they succeed.
Glenn Spencer, vice president of the U.S. Chamber of Commerce’s Workforce Freedom Initiative, said there are 18 states that allow their state constitutions to be amended by ballot initiative. Spencer said labor could have success in California, Colorado, Illinois, Massachusetts, Missouri, Montana, Nevada, Ohio and Oregon.

“Our fear is if it was to pass there, the unions would use this as a template to try to pass it elsewhere,” Spencer said. “There are a number of states that they could attempt to do this where unions remain relatively powerful. That's the worry, that this could spread.”
http://thehill.com/homenews/campaign...-constitutions