YOU mentioned all kids going to public schools, which implies that you don't think schools should be private, whether for primary, secondary or as you mentioned (for some inexplicit reason), post-secondary schooling. You also need to look at where the school funding is lacking, where it's being wasted and why. I can't say how it is in other places, but in Milwaukee, where the public school system only has about 78K students, the budget is over $1.3 Billion but their results are terrible. High dropout & truancy rates, really bad test scores and in some cases, the high school brags about their high graduation rate, yet the Math & Reading proficiency scores are in low double digits, if even that high.
Define 'properly funded'. Money for schools comes from property tax and in some cities, the tax base is shrinking because the home values are dropping. People from the inner city send their kids to private/parochial/suburban schools if they can and the voucher system allows this when the family doesn't have the money.
I can connect you to people who have serious problems with the 'education' their kids were or would have been subjected to, if you want- many enrolled their kids in private schools and they're not all Republicans- most are wealthy Democrats.
If you don't know what is being 'taught', don't tell me that I'm wrong.