“The sort of person who wouldn’t take their civic duty seriously and vote “not guilty” for a black accused of murder probably already has a felony conviction of his or her own and is ineligible to serve jury duty.”
You mean like the person on the Michael Slager jury who allegedly said that under no circumstances would he vote to convict?
Did he have a felony conviction?
You can’t generalize from one specific example. In order for Mr. Mystal’s plan to work, you need to have a large pool of people willing to do this in order to ensure you have at least one on every trial involving black on white crime.