A month shy of his one-year anniversary at CNN, Piers Morgan just posted his lowest-rated month to date in the key adults 25-54 demographic. His Piers Morgan Tonight averaged 154,000 viewers in the demo in November. That was down 4% from the delivery of his predecessor Larry King in the 9 PM slot last November. Meanwhile, in his first full month at 8 PM, MSNBC’s Ed Schultz drew 201,000 in 25-54. That was better than the 176,000 demo viewers Lawrence O’Donnell delivered in the slot in October. But it was down 35% from the performance of Keith Olbermann in the 8 PM hour last November. (O’Donnell too was down 35% from Olbermann’s October 2010 average.) Overall, Fox News once again led the cable news network pack in November with 258,000 viewers among adults 25-54, followed by MSNBC (138,000) and CNN (121,000).