The ironic Mr. Civil Rights
The racist attitude that dominated the American South in these times upheld an ironic point of view about the qualifications of African Americans as people. Racists often believed that black people were inferior to white people, and yet, Mr. Civil Rights, the powerful lawyer, Thurgood Marshall, literally disproves that myth by defeating racist agendas in court as a lawyer. His success and the success of the NAACP show that racism is founded on ideas about reality that are demonstrably false.
The irony of retrial
The retrial shook the whole nation and sent many conservative communities into mayhem. All across the country, the KKK became interested in a retaliatory kind of vigilante justice, and they lynched many black men in cold blood, just to demonstrate their distaste of actual legal justice. Their ironic response is so extreme that it can be seen as a measure of just how confident they were that the racist agenda would always have power in the government. The retrial is an outcome of real justice, but it is regarded by racists as absolute madness.
The inadvertent consequences of justice
As noted, the experience of actual justice was so offensive to racists throughout the American South that the KKK used the court case as a rallying cry. Their retaliation was cold-blooded murder in many cases. They lynched many young black men for nothing, and they murdered two of the defendants in the case. Even Thurgood Marshall is said to have been nervous for his life. All around him, racists with weapons threatened his life. The ironic outcome of true justice is assassination of those who fight for truth and justice.
The ironic sheriff
Notice how easy it is for Sheriff Willis McCall to get away with cold-blooded murder. His authority makes him somewhat immune from the consequences of his actions, primarily because he is white and he has the same racist political opinions as those around him. He is unjust, but his the same flavor of "unjust" as the community around him, so he is treated like a hero, and he gets away with murder. That adds an ironic undertone to the whole quest for justice, because these men might be innocent, but the literal sheriff is guilty of literal murder and gets away with it.
Privilege and victimhood
The ironic undertone of the book is that the white supremacists consistently treated this court case as if they were the victims of injustice. Imagine the irony of that. Their privilege has made them so used to absolute power that the very insinuation that Black Americans might actually be enfranchised to justice and power makes the racists across the country play the victim to the point of murderous revenge. The irony is almost unfathomable. Of course white supremacists are not the victim in American race relations throughout history.
