We believe that juries cannot always correct for deficiencies in the power structure of a community. In the South in those times, minorities were not represented on juries, and corrupt officials could stack the system against civil rights. Today's juries are much more diverse and representative of the community, thereby greatly decreasing the chances of injustice by jury. Even if an occasional acquittal did occur due to instructions about the powers of jurors, the good that can come from jury power for civil liberties and minority rights far outweighs an occasional failure. No one guarantees perfection with jury independence.
All human institutions are fallible.
But randomly chosen juries have proven over time to be less racially biased than other participants in the criminal justice system. The enemies of the concept of jury power have called it jury nullification. They had a George Washington law school professor named Paul Butler on who advocates that black people use jury power to acquit blacks accused of non-violent crimes. I believe that one should judge people on the content of their character, not the color of their skin. We believe he does untold damage to the prospects for jury power helping everyone, including blacks, by presenting the concept in racial terms.