I've thought that for a long time. It started when Clarke moved up his book date to coincide with the 9/11 commission. Then he claimed cover as "a Republican" when it later turned out he'd just voted in the primary---for McCain. (One of those "bitter" McCaniacs---the ones the media is usually so happy to identify?). Then (or Thus) he got bumped downstairs by the Bush NSC---I'll bet Condi's radar honed in on him as a backstabber from the get-go. Then Fox outed him with that "backgrounder" saying just the opposite of everything in his testimony.
The man's a liar and a Clinton tool. I think he was in on the Sandy Berger caper as well. I still can't believe the way that was covered up.
Anyway, for Clinton to fall back on Clarke gives Republicans the perfect opportunity to re-open the entire episode: what was Sandy Berger doing cramming Clarke's memos down his pants?!