Politico's Michael Calderone writes about the Dana Milbank-Keith Olbermann messy TV divorce, with more details about how it came to an end.

A source familiar with the situation told Politico that Milbank had been unhappy on the show for a couple of months and expressed this sentiment to friends. During the first week of July, Milbank spoke to executive producer Katy Karp about why he had not been on the show for a couple of weeks. At that point, Milbank was told that there was an issue among staff with something positive he said the previous month about Charlie Black, a McCain senior adviser.

An MSNBC spokesperson confirmed to Politico the conversation took place, but said the producer was joking. Milbank also told Politico, "I had long aspired to work at CNN and began contract talks a month ago. I have high regard for my friends at 'Olbermann' and regret that they are so angry about my departure."

One note: Katy Karp is a producer on Countdown. Izzy Povich is the executive producer.