Blame Cobranchi for this post. His blog pointed me toward Stanford political scientist and self-proclaimed liberal Rob Reich who has written a downloadable paper on "Testing the Boundaries of Parental Authority Over Education: The Case of Homeschooling". I say "self-proclaimed" because for all his references to "the liberal state" I have yet to see any evidence that he's ever heard of classical Lockian liberalism.
Let's take it from the top, shall we? In classic liberal theory, people are considered to have a natural right to life, liberty and property. Governments rule with the consent of the governed. Therefore, governments only pass laws which regulate or ban the actions of the people when there is incontrovertible empirical evidence that such actions present a clear and present danger to the health, safety and property of the people.
The standard example is alcohol laws. In general, the state cannot interfere with the individual's right to purchase and consume alcohol. However, the state can prohibit a person who has consumed too much alcohol from driving a car, because there is incontrovertible empirical evidence that drunk drivers cause an enourmous amount of death and destruction.
Now, let's look at homeschooling. Where is the incontrovertible empirical evidence that homeschooling presents a clear and present danger to the health, safety and property of the people? There isn't any. Every study of homeschooling that has been conducted so far shows it to be the safest and healthiest form of education around. Rob Reich comes out and admits this in his paper. Yet he still wants to heavily regulate homeschooling because of his belief that there's a problem with homeschooling which doesn't surface in any of the empirical evidence. Such a belief is incompatible with the principles of a classical "liberal state".