Rep. Jesse Jackson, Jr. (D-Ill.) has admitted he is “Senate Candidate 5,” one of six unnamed possible replacements for President-elect Barack Obama. Jackson said he was contacted by federal authorities yesterday in connection with the arrest of Illinois Governor Rod Blagojevich.

Though authorities wish to interview Jackson in connection with the case, Jackson said he has been told he is not a target of the investigation, ABC News reported today.

Senate Candidate 5 had an influential backer who approached Blagojevich about raising $1 million in exchange for seeing the candidate named to the seat. Jackson released a statement yesterday denying any connection to a quid pro quo deal and said he had hoped and pushed for an open and transparent process.

As we reported today, the FBI’s affidavit filed yesterday provides enough detail to guess at the identities of Senate Candidate 1, 2, 4 and 5. Rep. Jan Schakowsky (D-Ill.) says she may be Senate Candidate 3, who was only mentioned offhand in the transcripts, while Senate Candidate 6 is a wealthy Illinois resident.

Blair Hull, the 2004 Senate candidate who lost to Obama in the primary, did not return calls yesterday inquiring as to whether he was Senate Candidate 6.

–Reid Wilson