Would half of your state and local taxes pay the tuition for a year at a private school?
The academically strong private schools in this area (even the church supported ones) charge more in tuition than the average per-pupil price of the public schools.
In 2005 the average public school expenditure in the US was $8,700 per pupil. Many states were over $10,000, with NY being about $14,000. So yes, in general the savings would be sufficient to pay for a private education, although I suppose some parents might have to give up one of their BMW’s, or stop spending a couple of thousand a year on tobacco and alcohol, or scale back on other discretionary spending.
But the real issue is quality. Public schools are dominated by leftists who want to brainwash our children. Public schools are not competitive, and they attract and keep poor teachers. Education as a private enterprise offers the same benefits as other private enterprise: freedom of choice, competition for customers, and therefore high quality. The success of the American economy is driven by capitalism and freedom, not by government bureaucracy and a socialist agenda.