This all stinks to high heaven.
I think we're seeing the White House trying to rough up the Congress with (very credible) threats of investigation and arrest for corruption.
There's a few issues muddying the waters. There's the factual question of did Rep. Jefferson commit the crimes the FBI says he did? So far, the evidence looks pretty darn strong that he did. The results of that will be decided in court.
There's the problem of the Congress being unwilling to police its members using the structures and procedures created for that purpose. On this point, Mark Klieman is right - the Democrats have to do something drastic to force the Rethugs' hand on their "give 'em a pass" perversion of the process.
There's the problem of the FBI, never an organization noted for its adherance to democratic proprieties, busting into the offices of a sitting congress critter in the middle of the day. In their favor is the warrant. It may be shown that they had exhausted all other reasonable means for obtaining necessary evidence. The point is we don't know the legitimacy of their act, but we do know that it is a very bad precedent for an executive police bureau to go after people in other governmental branches without extreme extenuating circumstances. They may exist, but that case hasn't been made.
There is the problem of timing and targets. Rep. Jefferson is a black Democrat. He is being subjected to a level of search and seizure that Rep. Cunningham, a white, Rethug lackey, was not. Why, of all the corruption probes going on, was this person targeted, guilty or not? Maximizing political embarrassment for the Dems.
Finally, there is the leak of Hastert's participation, however tangential, in some investigation. That was a bully tactic, plain and simple. Was it ordered by the WH, or did the FBI do this bit of intimidation on its own? Both are equally bad prospects. While I'd love to see Hastert bounced out of there, I don't want him gone so badly that I'll approve of the FBI bullying legislators.
Rep. Jefferson needs to step down now to deal with the corruption charges, and he needs to not demean himself or the nation by claiming this is racially motivated. Period.
The FBI does not need its powers expanded, and they should not be rewarded for invading the Capitol. They have to prove that they had no other recourse in this case, and even then the choice of target and the timing of the raid remain suspect.
I'm agreeing with Mark Kleiman on this one - unless the Congress (and that means the Dems) get off their asses and enforce their own discipline, they will get no support when they try to fend off the assault of the exective branch for political purposes.
If the Dems do take back one or both houses in teh November election, I think you can expect more raids for less cause by the FBI.