You'd still have to fight the parents and the state and federal governments.
Not really.
You just ignore them and do what you feel like doing.
I've known two people who ran school boards that way. They got a lot done (it probably helped that they were both very smart, with one having an IQ of 160). The first one started a meaningful gifted program for HG+ kids, and the second one had the school system running at a surplus pretty quickly. Everything fell apart almost immediately after they left. Two years after number two was gone, they begged him to come back to fix the enormous deficit they'd already racked up. He had been paying attention to what they were doing and was disgusted. He told me there was no point if the other people from his tenure weren't there, too, which was not going to happen. Thus, there was no point to going back alone and then being blamed for what would have been continued decay. He was right.
