Jack Abramoff must be singing the song that never ends. The House Oversight and Government Reform Committee is expanding its investigation of the relationship between the convicted lobbyist and the White House.

From his Pennsylvania prison cell, Abramoff has continued to assist federal investigators in hopes of leniency in his pending influence-peddling trial -- witness in particular the renewed attention to Rep. John Doolittle and his aide Kevin Ring.

A key figure in this expanding inquiry appears to be Susan Ralston, the former Karl Rove aide who had previously worked for Abramoff and is now demanding immunity in exchange for her testimony. Given the lengths the White House went to to keep its records of Abramoff's visits secret, how concerned should they be about Ralston's potential testimony?