How many times have you read about a local public school receiving a million dollar gift from someone? Maybe a "public" college, but rarely a public high school or school district. For some reason, people who accumulate wealth tend to attribute that success to college rather than elementary school, so you'll see new biology wings at State College while public school students suffer through science classes without the fancy labs. We can't explain it.
Yes, local communities can raise money to improve schools. Many times, like in Menomonee Falls, academic or teacher-related improvements take a backseat to sports-related expenditures. For example, in a year that saw two well-respected teachers lose their jobs, the Falls was able to add new artificial turf to a field and tell the staff they had no choice but to use the money for that purpose.
Private schools can spend money in stupid ways if they so choose, but it's generally their choice. Money is not dependent on whether or not residents are on the more liberal or conservative end of the spectrum, either. If the school is doing what a charitable organization sees as positive, the school might get millions. Case in point, the Drexel Fund gave Hope Christian Schools $2 million over the 2016 summer, just as the state gave the same school voucher money, and local public schools (Menomonee Falls again) lost referendums to keep teachers in the classroom. The Drexels never thought twice about maybe donating to a local public school. Nor have the Schwans or the folks from Generac. I don't know, maybe Herb Kohl has helped public schools, but I'm not even sure of that one.
It just seems that private schools get more million-dollar gifts. And those can help when schools can't get enough from taxes.