School boards are supposed to be representatives of the parents. Sure, some parents are more powerful than others but that's the standard nature of politics, and school boards are the entry level to community politics in our system.

They are stepping stones to state reps and other positions of political influence.

20 to 30 years ago some Republican operative realized that if you wanted to take over the country he needed to pack school boards with rabid partisan people. That way he could seed the political system with people of his same ideology and then a while later they'd be able to take over the government. As you can see he was brilliant and it worked.

So when a school board is Republican controlled the ideology is the primary reason they were put there in the first place. They were recruited and ran for an office as a stepping stone having nothing to do with whatever the job is.