I agree that the politics of race and social degeneracy have made inner-city urban schools basically inaccessible for most whites.
I live in a suburb outside of St. Louis, and while I wouldn't send a dog to the St. Louis inner city schools, curiously both the Bosnian and Asian immigrants' kids tend to do very well there - even in the same high schools labelled as "failing" by the local paper & just about everyone.
Personally, while I do see that it's the state's job to provide public education (at minimum for the poor), I don't see that it's the state's job to provide support for religious private schools (which are really the only ones that a voucher would even come near to paying for, since non-religious private schools charge in the five figures, mostly.)
I agree that for many parents, homeschooling is not an option.
The middle-class is not going to see *any* relief in this department. Vouchers are going to be for the poor, period. What would be better than vouchers would be, let's say, a "double" tax deduction for contributions made to inner-city parochial school tuition scholarship funds. So if you donated $500 a year, you would treat that $500/year donation as an effective $1000 on Schedule A. Thus those who want to contribute to struggling parochial schools in the inner cities could do so.