Slaving used to be legal, and helping them escape was illegal. Anyone who helps slaves escape set it up with the full knowledge they are breaking the law.
This is not a valid rebuttal. Slavery and selling drugs are nowhere near the same thing, and by equating the two, you do a massive disrespect to those who fought for that. Slavery is a civil rights issue; selling drugs is not.
No you are conflating that since something is illegal ergo it's wrong. The point that you're missing is that laws can be wrong and can be changed. Just because something is currently illegal does not make it wrong.