Tough Guys
I don’t know the real reason they refuse to let Condi testify (although their “separation of powers” rationale is patent bullshit and unpatriotic, to boot.) I can certainly see a public relations reason why they might have done it, though.
Richard Clarke comes across as a no nonsense, take no prisoners tough guy. Just the kind of guy you’d expect to be in charge of counter terrorism. Condi, however intelligent and articulate she may be, exudes timidity and nervousness in public. The contrast wouldn’t be very positive for the Bush administration.
Dick Armitage, on the other hand, is from tough guy central casting. For those people who will just catch a glimpse of this hearing in passing, Armitage looks just as tough as Clarke. As Uncle Karl likes to say, “politics is TV with the sound turned off.”