Letterman’s partisanship has become particularly overt in recent years. Bush jokes were easy, sure, but I’d argue that since the Obama election, Letterman has become even more comfortable with his biases (occasionally at the expense of being funny). He spends a great deal of time in his monologues with yawn-inducing jokes about Romney’s silver-spoon background, and, as you may recall, strange attacks on Sarah Palin‘s daughter. From someone who makes north of $30 million a year, the rich-guy jokes seem shallow, if not hypocritical.

But that’s nothing compared to Letterman’s recent obsession with whether President Obama will ever get more credit for his accomplishments. He complained to Brian Williams last week: “What more do we want [President Obama] to do for us? Honest to God.” And on Wednesday night, he confronted Bill O’Reilly with the same question, as if O’Reilly was one of those people who hasn’t given the president his due. …

Letterman addressed the allegations of partisanship on Piers Morgan‘s show Wednesday night, conceding that “I have been guilty of appearing to be playing partisan politics. However, I’d just like to say for the record I am a registered Independent. You go where the material takes you.” He then cites “poor Bill Clinton” for how “desperate” comedians beat up on Clinton during the Lewinsky scandal, and then goes on to say that, for comedians, the George W. Bush presidency meant “our prayers have been answered.” (To Letterman’s credit: Bush was the Golden Age for hilarious presidencies.)