My 2 cents:
Amy has three problems: her tendency to want to play "fair and balanced" host (which often ends up with her taking a strangely neutral and often mute role in debates, or be led down a line of reasoning by the guest). Second, the general tendency in the left to spout muscular rhetoric within the clique but back off when someone more aggressive (or alternatively, more sophisticated) stares them in the face. So you have Krugman staring down at the table and mumbling incoherent bits in on-air debates, and even Chomsky getting shouted down by Buckley into a discussion of whether the US is the greatest nation in the world! (Chomsky's case is excusable since he does not "spout muscular rhetoric" but provides straightforward analysis). The less literate liberal'ish side does not seem to suffer this impediment as much: shouting down is an indispensable tool of the likes of Dershowitz or the Blogistan. Third, the reliance on pre-packaged theories and gotcha type thinking and rhetoric which reduces to mere silliness when met with sophisticated response -- not much dissimilar from the deer-in-the-headlights response of the creationists and such, or Nigel Tufnel's "But... but this one goes to 11".
This is one reason I am a guarded fan of Matt Taibbi. Despite his Rolling Stones Iraq series, he is a refreshingly straightforward and dogged bullshit-caller. Reminds me of an erstwhile LBO list-member whose name I won't mention out of chivalry ;-),
--ravi