"It's not that Obama can't speak clearly. It's that he employs the intellectual stammer."

"Not to be confused with a stutter, which the president decidedly does not have, the intellectual stammer signals a brain that is moving so fast that the mouth can't keep up. The stammer is commonly found among university professors, characters in Woody Allen movies and public thinkers of the sort that might appear on C-SPAN but not CNN. If you're a member or a fan of that subset, chances are the president's stammer doesn't bother you; in fact, you might even love him for it (he sounds just like your grad school roommate, especially when he drank too much Scotch and attempted to expound on the Hegelian dialectic!)."

Meghan Daum explains it in the LA Times. And, righties, quit mocking:

[T]he godfather of the intellectual stammer is arguably none other than the paterfamilias of the conservative movement, William F. Buckley Jr.... In fact, if the people critiquing Obama's meandering speech patterns were to see an old "Firing Line" segment, I daresay they would think Buckley was drunk or otherwise impaired.