I've heard an argument that schools are supposed to pay for themselves. The idea is that people who go to school end up in a higher tax bracket, so it's an investment, not merely public good. Similar arguments are made for parks and recreation; more open space, less noise, so less stress-induced heart attacks, which means more years being a taxpayer.

I think this is a toxic way of thinking of things, but I guess it allows even the most greedy politician to live with himself for not opposing schools.