Who is Smith Keen from The Pelican Brief and what is their importance?

Smith Keen is Gray S. Grantham's editor at the Washington Post, Keen has a strict "open door" policy, which Grantham breaks to tell him what he has learned about the Rosenberg/Jensen murders, including contact with the author of the mysterious pelican brief, who believes she is the intended victim in Callahan's murder. If Darby Shaw contacts Grantham again, this will be a helluva story requiring massive, flawless verification before it can run. Keen green-lights it, but wants to be updated hourly.