Valerie Jacobsen at The Bookroom explains, point by point. This is her last point, and it's something to think about:
"Finally, think about this…. HSLDA exists for the purpose of protecting families from federal and state aggression for the legal act of homeschooling. Since HSLDA does have a legitimate purpose for its own existence, it seems a little odd to presume that no families need protection from federal and state aggression if they do, in fact, commit illegal acts. If a law was passed that made homeschooling “technically illegal,” with fines and jail terms attached, I think HSLDA would be flooding the Internet with Calls to Action, enforcement promises notwithstanding."
(Hat tip to Sebastian.)