Ratings for Piers Morgan Tonight in the 9 00 p.m. time period on CNN have Fallen To the lowest level in the history of the cable news channel. The ratings dive -- the show is down 27 percent in total audience since Morgan took over the time period from Larry King and 32 percent in the key 25-54 age group -- reflects an overall plunge in ratings for the channel. Its primetime audience now averages just 446,000 viewers versus 690,000 for MSNBC and 1.79 million viewers for Fox News Channel. Taking note of the fact that HBO's The Newsroom , modeled after CNN and costarring Jane Fonda, debuted with 3.1 million viewers on Sunday, the Washington Post observed, "If CNN [were] fiction, and a premium cable network, and run by founder Ted Turner's ex wife, it might be doing just fine."