Teachers unions suffered yet another deserved but embarrassing defeat this week. In Arizona, the state Supreme Court found that not only did unions fail to submit enough valid signatures to get their anti-school-choice proposition on the fall ballot, but they also broke the law by hiring felons to collect signatures.

This is just the latest example of teachers unions wasting their members’ hard-earned money to fight against popular policies that most voters want. If it wasn’t clear before that teachers unions serve only their own narrow interests, not the public good, it should be now.