The numbers are in from the Chicago Teachers Union’s strike authorization vote, and it’s not even close.

After three days of voting last week, 22,678 of the union’s 24,752 eligible members cast ballots, and 96.05 percent of them voted “yes” — 88 percent of all CTU members. The nation’s third-largest — and arguably most important — teachers union has sent a clear message that they are willing to walk off the job amid their current round of contract negotiations, as they did in 2012.

For the CTU, this contract fight comes in the middle of a rare political crisis for the city’s political elites, yet will also prove a monumentally difficult task. But the strike vote itself (which gives the union leadership the authority to call a walkout if certain legal benchmarks are met during contract negotiations) and the recent history of battles around that ballot are worth recounting — both because a nearly 90 percent “yes” vote reflects the success of a crucial element of the Chicago teachers’ model of organizing, and because it’s the kind of lopsided result the union’s enemies previously thought was impossible to achieve.