Inside Indiana, both sides agree that the new right-to-work law will have a significant impact, though they disagree over whether the positives outweigh the negatives. The law specifically rules out labor contracts that require workers to pay a fee for union representation.
Unions in the state say the law may not hurt them right away, but they foresee a corrosive effect over time on union clout.
"It's going to be a while before we see the effects," says Ricky Wayman, an electromechanic at Verallia, a maker of glass beverage and food containers in Dunkirk, Ind. Mr. Wayman echoes the concerns of most union workers in Indiana who say that the measure's real purpose is to drive down union wages and, with them, the unions' political clout.
"Over the course of time we're going to have declining membership. New hires are going to see it as a way to keep a little more money in their pockets, which, in effect, will deplete local union funds," he says. It will deplete bargaining power and limit any kind of political action, he adds.
Proponents of the law see right to work as a pro-business effort to attract companies to the state, which will ideally lead to new jobs.
Many companies looking to relocate will rule out places that do not have right-to-work laws, says Rob DeRocker, an economic development consultant in Tarrytown, N.Y.
"The lack of a right-to-work law suggests that the mentality at the government level is that it's not a business-friendly state," Mr. DeRocker says. "Rightly or wrongly, it's an issue."
Right-to-work supporters also say the measure promotes the individual liberty of workers, giving them the choice whether or not to join a union – and perhaps more important, pay membership dues.