Michigan, home of the American auto industry and thousands of its unionized workers, is likely to be the latest state to sign so-called right-to-work legislation into law by next week.

Of course, labor and Democrats are not letting that happen without a fight.

Despite lacking the political power to stop the measure from advancing through the legislature Thursday, they are marshaling their troops in Michigan as the right-to-work push becomes the latest battlefield in the Republican-led war on unions.

Here’s a primer to what’s going on in Michigan this week:

What exactly are Michigan Republicans trying to do?

The state legislature is controlled by Republicans, as is the governor’s mansion. Their right-to-work legislation does three things: prevents unions from penalizing workers in union shops who decline to join and pay dues, exempts police and firefighter unions from those changes and prevents opponents from overturning the law by referendum.

MLive.com reported on more of the details: “Currently workers don’t have to join a union. But if they don’t, they still have to pay fees anyway. The legislation would no longer require employees to pay union dues or fees as a condition of employment.”

Republicans are using the intricacies of the legislative process in Michigan to craft the law so it can’t be overturned by referendum like Ohio’s SB 5 was.

What makes the Michigan fight different from other fights?

After being elected in 2010, the Gov. Rick Snyder repeatedly said he didn’t want to follow the conservatives in his party into a fight over right-to-work. Back in January, Snyder said tackling the issue would be the wrong fight at the wrong time. But Snyder had a change of heart after labor sponsored a ballot measure to write collective bargaining rights into the state constitution. That measure was overwhelmingly rejected by voters on Nov. 6.

Snyder blamed labor for putting right-to-work on the agenda. “I said it could stir up the whole topic that we’re discussing right now,” he told MLive.

It’s not surprising that Snyder would be reticent to have a fight over union rights in Michigan. About 18 percent of the state’s workers are union members, according to the U.S. Bureau of Labor Statistics, and the state’s best known employers — the car makers — are union shops.

What makes the Michigan fight similar to the others?

The cast of characters and the circumstances in Michigan are similar to those in other states where Republicans have gone to battle with labor. Republicans swept into power in the state in 2010, just as they did in state governments throughout the country. Their arrival in Michigan came with the push to enact right-to-work legislation, just as it did in Wisconsin and other states.

The GOP’s state House majority was reduced in the Nov. 6 election but no state senators were on the ballot, ensuring that body remained solidly in Republican hands. With their larger House majority still in effect during the final lame duck session, they moved on right-to-work.

That brought out the forces you’d expect. On one side were labor protesters, amassing at the state capitol in the style of the Wisconsin fight. Democratic legislators briefly walked out to support them, a move reminiscent of Democrats in Wisconsin and Indiana.

The conservative groups who stood by Republicans in other states during the right-to-work fight did the same in Michigan, though apparently with fewer supporters behind them.

The Koch brothers-funded Americans For Prosperity “had a large tent set up on the Capitol lawn, but it sat relatively empty throughout the day,” MLive reported. The group “blared speeches by Ronald Reagan” from their perch by loudspeaker.

What does it all mean?

It’s not entirely clear what Michigan’s law will do in real-world terms. Republicans see it as a panacea, lettings workers to pay union dues as they please and liberating employers from the yolk of organized labor. But economists don’t see it that way.

One Michigan economist told the Detroit Free Press that the right-to-work fight was “symbolic” and “likely would produce a minimal impact for the state’s economy and jobs market.” But there seemed to be agreement that right-to-work shift will result in declining wages for workers.

“The data on wages tell a fairly clear story: Of the top 10 states in per capita income in 2011, seven were not right-to work states,” the Free Press reported. “Of the bottom 10 states, seven were right-to-work.”

What happens next?

Labor organizations will regroup and go to court. Union organizers tell TPM they’re looking into challenging the Republicans’ contention that the new law is referendum-proof, as well other legal options surrounding the law.

Meanwhile, look for the left to paint Snyder — who tried to project a moderate, technocrat image — as a tea party extremist of the highest order. Labor groups are planning press events and other actions to tear down Synder’s image once he signs the right-to-work bill into law.

Finally, the left says they’ll make Republicans pay in the 2014 cycle. President Obama, who just won Michigan by a comfortable margin, is on record opposing the new right-to-work law, giving a boost to Democratic efforts to oppose it. Labor points out that legislators who supported anti-union laws in states like Ohio lost their jobs in the following election cycle. They hope to repeat that in Michigan in two years.