On Tuesday, teachers at the Acero network voted overwhelmingly in favor of a strike should contract negotiations stall. Here are five reasons why people in Chicago, and beyond, should pay attention to Chicago’s charter union industry.

It’s about more than just one school.

Acero isn’t the only school in tense negotiations. On Friday, teachers at another charter network, Chicago International Charter School, will take a strike authorization vote. In total, the Chicago Alliance of Charter Teachers and Staff (ChiACTS), which represents charter teachers in Chicago, is negotiating contracts with 11 operators this fall.

If any of these groups of teachers walk out, it will be the first charter strike in American history, according to union officials and labor experts.

Charter unions have private employers.

Unlike teachers employed by a school district, charter teachers have private employers. If teachers strike, they’re governed by the National Labor Relations Act, not the Illinois Labor Relations Act. Martin H. Malin, co-director of the Institute for Law and the Workplace at Kent Law School, said the economic pressure is much higher for striking charter teachers. “Under the NLRB, the employer may permanently replace the strikers,” he said.

It’s about more than just one industry.

In June 2018, the Supreme Court ruled in Janus v. AFSCME that labor unions could no longer collect fees from employees on whose behalf they negotiate, but who haven’t joined the union as full members. It was a blow to public sector unions, and many are still struggling to understand their future in the wake of the decision.

To Bob Bruno, director of the Labor Education Program at the University of Illinois at Urbana-Champaign, strike authorization votes like that taken by teachers at Acero are part of a broader political battle between pro- and anti-union forces. “Being able to marshal the resources to effectively wage and win a strike in the post-Janus era is a real statement to those political forces that believe that Janus would be the death blow to teachers unions,” he said, “particularly for the first time in the charter industry.”

The charter teachers are represented by one of the most militant labor unions in the country.

When ChiACTS voted to join the Chicago Teachers Union, it joined a body that has a history of aggressive bargaining. In 2012, thousands of CTU members went out on a weeklong strike that captured headlines across the country. They also pushed their demands beyond just wages and benefits to broader school-quality factors. This spring, CTU teachers will begin negotiating a new contract again.

Bruno said the charter school unionized employees being affiliated with the CTU means they carry some of the political force of the teachers union. “The probability of a strike is much higher,” he said.

The negotiations are taking place as Chicago gears up for a mayoral election.

Chicago’s school board is appointed by the mayor. That means whoever is elected to replace Rahm Emanuel will appoint the district’s board of education. Traditionally, mayors have worked hard to put their own stamp on the way school districts are run. At the same time, the primary charter PAC in Illinois is gearing up to spend millions on the mayoral and local aldermanic elections. A contested election plus millions of dollars related to education policy pouring into the city raise the stakes of already tense negotiations.

“This is part of a larger, corporate-backed, very conservative network of forces that have invaded the public school system and are trying to privatize it,” Bruno said. “Chicago gets set up as a battlefield for the charter industry.”