Well, it appears the FBI & Justice Dept. can actually still

investigate corrupt politicians.
Illinois Governor Rod Blagojevich and his chief of staff, John Harris, have been arrested and charged with a multitude of crimes involving everything from a “pay to play” scheme for state contracts to his attempt to sell the open Senate seat vacated by President-elect Barack Obama in exchange for “financial considerations” for the governor and his wife.

Prosecutor Patrick Fitzgerald calls the breadth and depth of charges “staggering.”
...
“They allege that Blagojevich put a ‘for sale’ sign on the naming of a United States senator; involved himself personally in pay-to-play schemes with the urgency of a salesman meeting his annual sales target, and corruptly used his office in an effort to trample editorial voices of criticism.”
Well, miserable little tyrants really don't like being criticized; it's bad for their self-esteem, you know.

And this is Illinois, after all:
But all of this occurred in the state of Illinois, where the arrest of Blagojevich makes it four out of the last seven governors arrested and charged with wrongdoing while in office.

Consider this last bit:
These are not the actions of someone who had a grasp of the enormous legal trouble he was in. The fact that he was so reckless and cavalier about his wrongdoing may indicate either a soul so corrupt that right and wrong had no meaning for him or he was suffering from delusions associated with his office so that he may have thought he was untouchable.
You have to remember, this is Chicago, IL. He was probably pissed that he was being investigated at all on the previous stuff; after all, that's the way it's done in Chicago. He was probably figuring that with all the connections, if he was indicted, there'd be a way found to throw it out or get him some deal in exchange for being quiet about all the others involved in it.

I guess you could say the spirit of Capone lives on.

Now if they can just bother to investigate Frank and Dodd & Co....