Now, according to Josh Marshall, it looks like we can add Bush personally to that list :

What this is about isn’t Condi Rice or Richard Clarke or even George W. Bush. It’s about what happened — finding out what happened. One side wants to find out; the other doesn’t. This whole story turns on that simple fact. Why else try to destroy Clark unless what he has to say is profoundly damaging? Liars are usually easily discredited; it’s the truth-tellers who need to be destroyed.

This administration has used and continues to use literally unprecedented means to maintain secrecy in order to keep this information — what happened — bottled up in the White House and in other parts of the executive branch.
. . .
Yet Clarke’s new enemies now want to use the fact that they control the Justice Department and the process of declassification to knock him out because he is, to all appearances, trying to bust open that very vault of secrecy.

In other words, precisely the tools these folks refuse to use in the interests of keeping everything secret they are more happy to use to crush someone who is opposing them.
. . .
(Bear in mind that top White House aides have told the press that the president personally initiated and is directing this campaign against Clarke. Not outside rabble-rousers, not nefarious aides operating on their own account, but the president himself. This is all his doing, according to his own staffers.)

The more the Republicans fight dirty against this guy, the more I believe him. I’ve seen enough mob movies to know that if the big boss is doing his own hits, he’s gotta be really pissed. Maybe Bush is the one who’s striking back “like a wounded animal”….