Illinois unions are empowered by some of the most union-friendly collective-bargaining laws in the country. Illinois lawmakers make it compulsory for state and local governments to bargain with public-sector unions over a host of issues. They also give public-safety workers the power to force arbitration and allow teachers to strike—one of only 13 states to do so. Gov. J.B. Pritzker signed legislation last year that expanded the number of employment issues the CTU can strike over.

States like North Carolina, Texas and Georgia, by contrast, put the needs of taxpayers before those of their public-sector unions. Those states ban collective bargaining with teachers unions altogether.

Chicago’s leaders have emboldened the CTU by consistently giving in to its demands. Former Mayor Rahm Emanuel folded twice, first in 2012 after a weeklong strike and then again in 2016 after a one-day walkout. Mayor Lori Lightfoot has appeased the union several times.