“Gingrich is hurting himself, with this promotion of a NY Times hit piece, more than he is hurting Romney.”
....and Romney used liberal sources to go after Gingrich.
No, conservatives want to see Romney hit....lol, perhaps you come from a different perspective.
You don't need "liberal sources" in order to quote someone's record, which is what the PAC did. Also, Senator Tom Coburn is well-known as one of the most conservative legislators in office and he revealed Gingrich's record in an unflattering light in his book, Breach of Trust.
I'm not sure the anti-Romney crowd is all that "conservative" anyway.