In thinking about other possible subjects for a compelling biography, one person that comes to mind is John W. Davis, who was the leading Supreme Court advocate of his era. Davis argued over 100 cases to the Justices as Solicitor General and in private practice, including The Steel Seizure Cases (which he won). He was also a Congressman, the Democratic nominee for president in 1924 (he lost to Coolidge), and a leader of the bar for decades.
Davis is unknown (or infamous) today because he argued the segregationist position in Brown. Why did he take the case? The obvious answer is that he was a racist, but the truth appears more complicated. In 1924, Davis fared poorly in the general election partly because Southern Democrats viewed him as too liberal on race based on his record as SG. How did that guy become the villain in Brown? I don’t know, but I’m going to try to learn more.