TRENTON, N.J. — Twenty new subpoenas issued in a traffic jam scandal that has shaken Republican Gov. Chris Christie’s administration reach deep into his office and his re-election campaign but spare him.

Christie’s chief of staff, chief counsel and top communications strategist are among those being compelled to produce e-mails and text messages related to an apparent political payback scheme to cause massive traffic jams last fall by closing local access lanes to the George Washington Bridge.

Christie’s two-time campaign manager and regional political director were also subpoenaed, as were three people close to Christie whom he appointed to the agency that oversees the bridge. Two of them have resigned.

The subpoenas seek text messages and e-mails that could shed light on the traffic jams plan.

Christie has apologized for the traffic jams and said they blindsided him.

Christie is not a target of the investigation, said Democratic Assemblyman John Wisniewski, who is heading the probe.