As we reported Wednesday, Republicans in Congress are blocking any more embarrassing investigations into the misuse of reconstruction funds for Iraq by denying the special inspector general jurisdiction over the new funds they're appropriating.

Today's news brings a variation on the theme. As Think Progress is reporting, the Justice Department's Office of Professional Responsibility has closed its investigation into the role Justice Department lawyers played in approving the president's warrantless spying program because the Bush administration has denied security clearances to the OPR investigators who would have done the work.

In a letter to Democratic Rep. Maurice Hinchey, the OPR's H. Marshall Jarrett says the OPR made a "series of requests" for the necessary security clearances beginning in early January. "On May 9, 2006, we were informed that our requests had been denied," Jarrett writes. "Without these clearances, we cannot investigate this matter and therefore have closed our investigation."

Hinchey's office says he wants to know who denied the security clearances so that he can "reach out to those responsible for stifling the investigation" and "identify a way for a probe to resume."