He has had one of the most meteoric rises in cable news. But controversial Fox News firebrand Glenn Beck may be losing some of his appeal. In January, Beck’s eponymous talk show posted the steepest ratings declines for any cable news program. Glenn Beck averaged 1.8 million viewers, down 39% vs. January 2010. In 25-54, the drop was even bigger, 48%, to 397,000. Some of the losses could be explained by tough comparisons to last January, which was one of the highest-rated in Fox News’ history, fueled largely by coverage of the Massachusetts governor race. Still, this is a very steep decline for Beck, who peaked at 2.8 million viewers in 2009, drawing more viewers than all of his cable news competitors combined. Beck, who has been an icon for conservatives and a lightning rod for his critics, has had a rocky ride on Fox News. His highest point came last August when his Restoring Honor rally drew almost 100,000 in Washington, DC. But Beck has also come under fire for his attacking style and controversial remarks, including his 2009 statement that President Obama was a racist that led to in a number of advertisers pulling from his show. As of Sept. 2010, 296 advertisers had asked not to be on Glenn Beck, up from 26 in August 2009.

Also hard hit in January was Fox News’ On the Record with Greta (1.5 million, down 36%; 333,000 in 25-54, down 49%). Other cable news channels with big ratings declines include CNN’s Anderson Cooper 360 (595,000, down 34%; 174,000 in 25-54, down 43%) and CNN’s Parker Spitzer (478,000, down 39% from last year when Campbell Brown was hosting the 8 PM hour; 125,000 in 25-54, down 46%).