Les Moonves, chairman and chief executive officer of the CBS Corporation, responded to criticism that the network was replacing David Letterman, a liberal comedian and longtime host of the weeknight Late Show program, with Stephen Colbert, another liberal comic and host of The Colbert Report, who is likely to continue making fun of conservatives and Republicans when he leaves his Comedy Channel program to replace Letterman sometime in 2015.

“Ironically, Stephen Colbert is much more moderate than people think he is,” Moonves said on Wednesday. "He's a great social commentator, and that's sort of what we want. That's sort of what David Letterman has been."

David Letterman shocked the late night talk show world, last week, when he announced he was going to retire in 2015. But over the last few years Letterman had been losing the ratings war to his less liberal competitor Jay Leno. While Leno tried to be more even-handed in his jokes against Republicans and Democrats, Letterman took a decidedly leftist turn. A recent study of Letterman’s 2012 campaign jokes found he took more shots at Mitt Romney (44) than Barack Obama (9).

In the 2000’s Letterman throttled Republicans like George W. Bush and Dick Cheney, questioning if they had any “humanity.” He also conducted his own personal war on GOP women as he called Michele Bachmann a “whacko” and depicted Sarah Palin and her daughter in “slutty” terms. But when it came to Obama, Letterman was positively awe-struck when the President came on his show, as he gushed “how satisfying it is to watch you work.”

Television history was made last night when a guest on "Late Show with David Letterman," for quite possibly the first and last time, used the words "murdered" and "aborted" in the same sentence.

The person doing the talking was former president Jimmy Carter, who's making the rounds to plug his new book, "A Call to Action: Women, Religion, Violence and Power." (Video after the jump)

Appearing on Thursday's CBS Late Show aired early Friday morning, former NBC Nightly News anchor Tom Brokaw discussed the Russian invasion of Ukraine with host David Letterman and observed: "...when chemical weapons were used in Syria and they were discovered, I didn't think it was President Obama's finest moment. He said there's a red line, then he kept moving that sucker....[Vladimir Putin] might have taken the measure of President Obama and said, 'I may be able to test this guy'....it has that appearance." [Listen to the audio or watch the video after the jump]

That analysis was prompted by Letterman noting: "And people are saying this [Russian invasion of Ukraine] is because of the negotiations, or the unilateral negotiations regarding Syria, when he [Putin] stepped in looking for weapons of mass destruction...and Obama had to sort of acquiesce that because it was not a bad idea. So now he [Putin] feels like he can get away with this. Is that part of it?" Brokaw replied: "Well, I think that's pretty astute."

Every year, in the days before Christmas, toy expert Shannon Eis goes on CBS’s Late Show with David Letterman to show off the hot toys of the season. But this year, she was greeted Wednesday night by a “Grinch” Letterman disturbed by “$20 billion a year on toys. 20 billion dollars a year!”

“I wonder if we should take some of that money and put it elsewhere,” Letterman ruminated. “I don’t want to be the Grinch here,” he deflected before being just that, fretting “but people in this country need food.”