When the local elections comes around, vote out the school board...
The Marxist teachers unions are extremely well-funded and highly well-organized politically. They also have a small army of Useful Idiots in the PTA willing to do their bidding. The communists get the school board members that they put up.
The most effective way to fight this is to pull the money plug that is attached to every school child. Remove the child from the school and the money attached to that child disappears.
Fewer kids=less money to the schools
Fewer kids=fewer = classrooms needed
Fewer classroom=fewer teachers and principals
Fewer kids= Less support for the government schools in the voting booth