I'm delighted the FBI nailed William Jefferson.
I hope it's true that the FBI is going to nail Dennis Hastert.
But I don't think we want the FBI to have the authority to raid Congressional offices anytime it can get a judge to sign a search warrant. Consider the prospect of such searches to investigate which officials gave classified information to the Hill.
The leak about the Hastert investigation, coming just a day after Hastert's public protest about the FBI raid on Jefferson's office, suggests that the Bureau hasn't lost its taste for dirty tricks aimed at its critics. Even in the face of Congressional scandal, we should be worried about yet another FBI power grab. We don't want anyone ever again to have the power that J. Edgar Hoover had, least of all someone running what is still very much the agency Hoover built.
But politics abhors a vacuum. If the Congress won't police itself, it can't plausibly, or successfully, object to the Justice Department doing the job. The Ethics Committees of the two Houses need their own investigative capacity, including powers of subpoena and search, and those investigators need to be able to act without getting permission from Democrats to investigate Democrats or from Republicans to investigate Republicans.