sorry, but equating the slave trade to the Zimmerman/Martin case is a level of hyperbole that not even LG has yet to descend to
It is not equating the slave trade; it is drawing parallels between the Fugitive Slave Act (1840s) and the "Stand Your Ground" laws. The transatlantic slave traded ended prior to 1820, right?
The parallel that is being drawn is that the one who commits the offense (either the one tracking down a fugitive slave or one who kills another in "self-defense") must simply be taken on his word, if there is a dearth of evidence to rebut. So, one who is killed no longer has the ability to rebut the testimony of the one who claims self-defense; sans any other evidence, then one can get away with a clean crime simply by declaring the he killed in self-defense; a slaveowner could simply claim that blacks were his slaves, the particularly black person in question was not given any credence if he stated otherwise (external evidence was required to rebut the claim of the slaveowner).