CNN Special Report Season 2 Episode 11 The White House Correspondents' Dinner

Of all recent presidents, Obama has taken humor closer to the hard-to-define threshold of what is appropriate coming from the mouth of a president. Sure, like his predecessors he usually opens with the regular ribbing of the press and his staff and greases the way for his biting attacks with self-mockery, poking fun, for example, at his penchant for teleprompters or his allergy to D.C. backslapping. But Obama's jokes can also be daring and cut deep. With adept comic timing, the president -- whose political enemies have often put his image through the shredder -- leads his audience right up to the line ... and sometimes over it.