Who is Tobias Simon from Gideon's Trumpet and what is their importance?

Simon is a Miami lawyer who was put in charge of Gideon's retrial. He's a lawyer from the American Civil Liberties Union and spends many hours on the case before meeting Gideon. When that meeting takes place, Gideon declines Simon's representation saying that he wants to select his own attorney. Simon later writes that Gideon was a "nut" and that it's a shame that the course of legal history was changed on the basis of an appeal by such a person.