How does he get away with it? Here's my theory.
Joe Biden sets up an irreconcilable dichotomy in your brain. On the one hand, he's been a senator for 36 years and is the chairman of the Foreign Relations Committee. On the other hand, he talks like Cliff the Mailman from Cheers, making one preposterous statement after another. When he says something paralyzingly stupid, your brain cannot reconcile the idiocy of the comment with his tenure in the Senate. You automatically doubt your grasp of the facts because you cannot believe there's any way such a nincompoop could have achieved the success he has. Reporters interviewing him wonder if they should press him on the issue, but decide against it because there's no way he could be that ignorant given his past. Afraid of making themselves look foolish by asking a stupid question, they stay silent and let the conversation move on.
Well, either that or the MSM is totally in the bag for the Democrats.
Update: A Monk of Miscellaneous Musings posts this marvellous assessment from the press of Cliff the Mailman's perceptive wisdom:
Biden's command of the issues was simply of a higher order. Palin didn't have a single moment as impressive as Biden's short discourse on the vagaries of recent U.S. policies regarding Israel, Hamas and Hezbollah.Outstanding! He gets kudos from the MSM for making stuff up.
Wombats. They rule the world.