Arizona’s educators are set to begin striking today. With a school system covering a million students, the walkout will be the largest yet in the current strike wave. It will also likely be the most contentious.

For years now, Arizona has been ground zero for the implementation of a host of reactionary policies, including tax cuts for the wealthy, school privatization, and racist anti-immigrant crackdowns. There’s every reason to expect that it will take a massive and sustained work stoppage to force Arizona’s Republican elite to grant educators’ demands for increased pay and school funding.

Despite the unfavorable political context and the absence of strong labor unions, Arizona’s teachers and staff are remarkably well-prepared for this struggle. Led by a dynamic group of young rank-and-file militants, tens of thousands of educators have managed to cohere into a formidably organized force in less than two months. Given the strength and intransigence of the contending sides, Arizona appears to be on the brink of a particularly explosive political battle.