House Speaker J. Dennis Hastert (R-Ill.) expressed alarm at the raid. "The actions of the Justice Department in seeking and executing this warrant raise important Constitutional issues that go well beyond the specifics of this case," he said in a lengthy statement released last night.
Well, ok, so maybe they're not immediately outraged about the same things that people outside Congress are ( House Minority Leader Nancy Pelosi and Senate Leader Bill Frist have expressed similar sentiments). The "constitutional issues" that Hastert refers to supposedly stem from the "speech and debate" clause in Article I, Section 6:
They [senators and representatives] shall in all cases, except treason, felony and breach of the peace, be privileged from arrest during their attendance at the session of their respective Houses, and in going to and returning from the same; and for any speech or debate in either House, they shall not be questioned in any other place.
Of course, the text on its face refers only to arrests, and makes no reference to investigations or the execution of search warrants unrelated to a representative's "speech and debate". Moreover, even in the realm of arrests the exception for "treason, felony, and breach of the peace" has been interpreted very broadly, to encompass virtually all modern crimes (see this annotation from the Cornell Legal Information Institute). As former assistant attorney general Viet Dinh explains in the article, "the raid on [Jefferson's] offices itself does not define a constitutional issue."
If I were Hastert, Pelosi, or Frist, I would be more worried about whether my members were selling their offices, and the electoral consequences of that discovery, than trying to stigmatize the FBI for aggressively investigating corruption.