With some 12,000 union-aligned protesters amassed around and inside the capitol in Lansing, Mich., Republicans formally made the labor stronghold America's 24th "right-to-work" state on Tuesday. Gov. Rick Snyder (R) signed the law in the afternoon, so on March 31, 2013, public-sector unions will no longer be allowed to require membership or dues from the workers they represent, and the same holds true of private-sector unions when their current contracts expire. The unions and their Democratic supporters were not pleased, and they aren't ready to throw in the towel. "This is just the first round of a battle that's going to divide this state," Teamsters chief James Hoffa tells CNN. "We're going to have a civil war." But what options are really open to Big Labor? Here are some lessons from three other Upper Midwest industrial states in which Republicans recently pushed through similarly anti-union laws:

1. The Ohio option
In March 2011, Ohio Gov. John Kasich (R) and the Republican legislature enacted Senate Bill 5, a law aimed at public-sector unions, banning strikes and limiting their rights to collective bargaining; in November 2011, voters overwhelmingly overturned SB5 in a public referendum. Michigan Republicans have tried to avert a similar outcome by exempting the powerful police and firefighter unions from their new law, and by attaching a $1 million appropriation measure on the bill — in Michigan, spending bills can't be overturned by legislative referendum. 

But unions believe they have found a way around this roadblock, or actually several ways. According to an analysis by the Citizens Research Council of Michigan, unions should be able to force a popular vote on the law either through a "voter referendum" — which, unlike a legislative referendum, can include spending bills — or the "statutory initiative," which requires a higher signature threshold (almost 260,000 voters) but is more promising legally. If they get the signatures to reject the law, the legislature gets a vote on the measure, and if it's rejected (as expected), it would appear on the November 2014 ballot. 

The benefit of this route, says Greg Sargent at The Washington Post, is that "Snyder will be heading into re-election in 2014 up against a heavily energized union base, a ton of money pumped into the state by national unions — even as there's a major pro–collective bargaining initiative on the ballot." Or, as a nameless union official put it, "it will be Thunderdome for Gov. Snyder and Michigan for the next two years." The law would be in effect, but the sting wouldn't be all that bad: The United Auto Workers' (UAW) current contract, for example, lasts until 2015.

2. The Wisconsin option
Unions in the Badger State responded to Gov. Scott Walker's (R) enactment of a sweeping 2011 anti-union law by trying to recall him and enough Republican state senators to reverse the law. The 2012 recall vote was mostly a flop for Big Labor — Walker easily kept his job and Democrats only unseated three of the 10 GOP senators they targeted, winning the State Senate for a short while to no real effect. Wisconsin Republicans, like those in Michigan, exempted firefighters and cops from their law.

Michigan unions have raised the possibility of trying a similar maneuver before the 2014 election, but the Wisconsin failure makes this option less palatable, and unions would have a big, expensive endeavor on their hands: Along with Snyder, the GOP will still have a 59-51 majority in the House next year and a 26-12 advantage in the Senate. Plus, as Joshua Spivak notes at The Recall Elections Blog, the GOP-led legislature "apparently recognizes the danger and is trying to make significant changes to the recall law." On top of that, unions and Democrats would have to drum up about 806,000 valid signatures, versus the less-daunting 540,000 needed in Wisconsin.

3. The Indiana option
Republicans like this option, for obvious reasons: In February, Indiana Gov. Mitch Daniels (R) signed the first right-to-work law in the industrial Midwest since — well, since Indiana scrapped its similar law in 1965. Unions and Democrats protested, but have been unable to do anything about it. So the Indiana option for unions is, in effect: Take it, and try to adapt to the new reality.

Synder used the threat of losing jobs to Indiana as a rationale for his surreptitious, abrupt about-face to support a right-to-work law. And that "had to sting," says Alex MacGillis at The New Republic. "Michiganders have long prided themselves on their superiority — literal and otherwise — over their Midwestern neighbors," and chasing after low-paying jobs against the Hoosiers must be particularly galling. At this rate, "the low-wage Midwest may become Canada's Mexico — who knows, with global warming, the Great Lakes beaches may even attain spring-break status in the decades to come."

The big problem for Michigan, and Big Labor in general, is numbers. As unions' memberships shrink, so does their power — as Michigan unions inadvertently showed in their own pre-emptive strike: Labor got a constitutional amendment on the November ballot to enshrine collective bargaining, fought hard for it, then saw it lose even as President Obama handily won the state, says Rich Yeselson at The American Prospect.

The loss provided what is called in an organizing drive a convenient "headcount" for corporations and their conservative Republican allies. The headcount said simply that the UAW and allied unions did not have the unqualified support of most Michigan voters. The unions could, and are, making some noise, but they wouldn't create sufficient civil strife to defeat a right-to-work flip. The unions could be rolled, the more quickly the better, even during a lame-duck session. The savvy president of the UAW, Bob King, one of the most progressive union leaders in the country, promises not to give up and threatens recall elections. But state right-to-work laws have only been repealed once, in Indiana.

And we know how that ends.