On Tuesday, Michigan became the 24th state to pass right-to-work laws, which prevent unions from compelling workers to pay union dues. It's a big hit to organized labor, which has historically had a strong hold in Michigan, the birthplace of the United Auto Workers Union. Advocates say that right-to-work laws stimulate economic growth, but opponents argue that they undercut pay for middle class workers. Only 12 percent of American workers belong to a union. What's behind the dramatic changes in labor union power? Who benefits from right to work laws? What role did politics play in Michigan?