I think Sowell is probably as good a man as a conservative can be, but a favorite quote applies to him:

"It is difficult to get a man to understand something when his salary depends upon his not understanding it." -Upton Sinclair

How poor people could pay for education in a private system, I haven't a clue. That the US has an awful education system, I completely agree, but that means it should be modeled after a much more successful system, like Iceland's.