Michigan became the 24th state to adopt a "right to work" law—the controversial provision that prohibits unions from forcing workers to join and pay dues.
But while the issue is politically charged—protesters marched in the capital of Lansing during Tuesday's voting—Michigan's move is partly a matter of economic survival, some analysts say.
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"Michigan is making this move because it saw Indiana do it," said Robert Sikkel, a labor expert in Grand Rapids, Mich. "They're afraid businesses may move to Indiana. Other states are going to look at this too to see if it's best for them."
Though right to work laws have been around since the 1947 Taft-Hartley Act, the movement has been growing since Wisconsin fought a similar battle with unions over two years ago. (Read More:Key Facts in Michigan's Fight Over Labor Laws)
"More and more states are looking to improve their economies and become more attractive to businesses and this is seen as one step toward that," Sikkel said.
In essence, right-to-work laws prohibit mandatory union membership and initiation fees while allowing non-union employees to receive the same wages and benefits. Pro-labor forces say the laws are aimed at stopping union membership and keeping wages low.
"We've been fighting this issue for decades and when there's an opportunity for it like in Michigan, business groups and anti-labor try to bring it about," said Chris Rhomberg associate professor of Sociology at Fordham University. "It's definitely aimed to stop unions."
Yet right-to-work advocates argue that no person should be forced to to provide financial support for a labor organization as a condition of employment. They also contend that states with right-to-work laws experience better economic growth, though they admit the research is murky.
The Economic Policy Institute, a non-profit, non-partisan think tank, says the laws and other anti-union measures lower wages—for both union and non-union workers alike—by an average of $1,500 per year, after accounting for the cost of living in each state.
And EDI says the laws have had no significant impact on attracting employers to a particular state.
"The freedom to choose (that) right-to-work supporters talk about so often is the freedom to treat employees however they please and to pay them as little as possible," said Ross Eiseberry, vice president of the Economic Policy Institute,
But some analysts say states suffering economically are looking at right-to-work laws as a matter of survival.
"Michigan has not been competitive economically with right-to-work or non-right-to-work states, " said Timothy Nash, an economist at Northwood University and an author of a recent report on comparative work issues in Michigan and other states. "I'm not pro or anti-union, but right-to-work laws are a way to be open to policy and economics."
Nash points to Texas—a right-to-work state—and Southwest Airlines as a place where unions and non-union feeling can co-exist.
"Southwest is based in Texas and is heavily unionized company. Some 95 percent of workers there belong to a union," Nash said. "It's still a top place to work and was profitable in the recession, so it shows how the two sides can get along."
What is clear is that more states are weighing right-to-work laws. Research by the National Conference of State Legislatures shows that several states in New England and in the northern Midwest are now considering right-to-work proposals.
And efforts to have a national right-to-work law may come up in the next session of Congress.
Republicans in the Senate introduced a right to work law in 2011 that would cover every state. It never came to a vote, but congressional supporters say they plan to introduce it sometime in the future.
And Republican governors of Wisconsin and Ohio have led efforts to curb or eliminate collective bargaining rights for public employees' unions.
In the end, analysts say there's no getting around the politics of right-to-work legislation. Any kind of trend across the country for passing right-to-work laws will depend on who controls state politics.
"More conservative interests are aligned with right to work laws," said Jason Bent, a professor of labor and employment at Stetson University's college of law. "The whole issue falls pretty much along political lines."