Who is Archibald Manning from The Pelican Brief and what is their importance?

Archibald Manning is justice of the U.S. Supreme Court, Manning cooperates with security and is said to be afraid of his shadow. He becomes the senior justice after Abraham Rosenberg's murder. When the justices discuss motives, Manning says he often wants to shoot Rosenberg himself, despite loving him as a brother, as he gradually becomes a symbol of what is wrong in the U.S. Manning is sure that the motivation is retribution. Hating both flying and funerals, Manning does not go to Providence for Jensen's funeral.