"The fact that none of these are over 50% should be more shocking."
Among the many dark legacies of "The Greatest Generation" was letting government employees unionize against us, in this case for instance, local parents are no match against a vast, wealthy, all powerful, national teachers union.
Special interest groups are.
I have taught in Indian villages where 80% of the parents were drugged out & boozed up most of the time. Kids were all FAS, never pass benchmarks, and over half were dead before the age of 25; maybe alot like DC.