I want to fight a new school uniform policy, what can I do?

Such is the political process in our democracy. Nothing illegal about the school board vote, so get 'em at the ballot box. Make it an election issue. Get petitions, walk the blocks getting signatures of like minded people for support. Put your name and few other like-minded names on the ballot for the next election. Run a campaign.

This is how things work in our democracy. It is the worst system, expect for every other government system in the world. Good luck.

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Vote them out. My wife and I have problems with our school board and the only option is to organize a campaign against them. If no election is near circulate a petition. And good luck to you.