If that is so, why do you have such a problem with his legal arguments when they are supportive of the south?
You seem to have overlooked the fact that he was an abolitionist. He was not justifying slavery, he was condemning the Constitution, which he soured on because it did NOT abolish slavery.
A word of warning ... don't try to portray Spooner as a defender of southern slavery on any forum where Spooner's positions are more well known -- you will be seen as a laughable baffoon.