... Robert Mueller, sixth Director of the FBI.
... Former Solicitor General Theodore Olson (whom I recently interviewed).
... Judge Laurence H. Silberman, who currently teaches at Georgetown University Law Center.
... Former Deputy Attorney General James B. Comey.
... Patrick Fitzgerald, DOJ Special Counsel (of Lewis Libby fame).
(Of course, Chertoff was floated big time yesterday. And others have suggested a Senator.)