I'm one of the few teachers in a TEXAS school that would probably be labeled right wing even though my economic philosophy aligns with the French philosopher Proudhon and the American heterodox economist Henry George.
Nearly half my district moved to devote an entire week to teaching Black Lives Matter. I had to go to the district meeting and point out that their proposed curriculum violated civil rights law to get the idea scrapped & I suspect I only succeeded because the state recently put my superintendent on alert for telling people to vote for politicians who oppose school choice.
You need to make sure your child's English & Social Studies teachers know at the start of the semester you will go ham on them if they try to be partisan. I teach science - physics - so I'm mostly immune from ever having to deal with controversial topics but I've had students try to get me to talk about politics and I refuse. I want to say I'm not the exception to the rule but that's increasingly not the case.
An easy way to solve this is to kick the government out of the education business. Have the separation of education and state similar to the way we have church and state. Vouchers is a good start in that direction. Once you put parents back in charge, the problem will solve itself.
The most powerful political lobby in too many states is the teachers union. I agree with you that this is necessary, but this will take a concerted, coordinated effort.
That is another thing that needs to stop. Nobody has a right to unionize against the tax payers. Can I go on strike for paying taxes?