The Washington Post’s Dana Milbank has ended his four-year relationship with MSNBC’s Countdown, and it’s not on the best of terms.

Milbank, who, because of a partnership between his paper and the NBC cable news channel, has been a part of MSNBC’s programming since at least the 2000 election. The end seemed to be sealed with a column he wrote last Wednesday describing Sen. Barack Obama as the “presumptuous nominee.” That set off a firestorm of discussion on all three cable news channels last week. The column also drew the ire of Countdown host Keith Olbermann.

So, last night on Countdown (clip after the jump), Olbermann said, “We had decided not to have Dana on this news-hour again until this was cleared up, and, sadly after some very happy years, he’s apparently chosen to make that cloud permanent. Good luck, Dana.”

Olbermann went further on his pre-Countdown post on the Daily Kos writing that Milbank would not be returning to the program, mainly due to his inclusion of the following Obama quote, which many have said was taken out of context: “I have become a symbol of the possibility of America returning to our best traditions.”

So where did Milbank end up last night? On CNN, opposite Olbermann. And what does Milbank say about this? What he told TVNewser, after the jump…

As for his MSNBC departure and arrival on CNN, Milbank tells TVNewser: “It predated the column and nothing occurred along the lines Keith described.” A week ago tonight, Milbank appeared on Countdown and was identified as “MSNBC political analyst.” An insider tell us Milbank’s contract with MSNBC expired earlier this year.