Did Glenn Beck just post a new ratings low for 2010?

It sure looks that way, as Beck's ratings continue to sag.

Bottom line: Over the last nine months, Beck gained and then lost nearly one million viewers. Trust me, in the world of cable news, that's not small feat.

Based on the numbers I've been surveying, it looks like Beck hit his (non-vacation) 2010 low last week, on April 9, when Nielsen tagged his audience at 1.96 million. By way of comparison, during late January, Beck was averaging more than 3 million viewers each night. And since September of last year, Beck had been averaging approximately 2.5 million-plus viewers each night. But recently, in the wake of the health care reform passage, those numbers have been heading south. Fast.

Based on the Nielsen numbers, here's a look at Beck's average daily rating over the last month.

You'll note that aside from a temporary spike that came on March 22, the Monday after the historic health care vote, Glenn Beck has spent the last four weeks with between 2.5 million and 2.0 million viewers, which represents a downward trend. (You'll also note a low of 1.76 million viewers on March 31, but Beck was off on vacation that night.)

In terms of the longer trend, Jed Lewison at Daily Kos recently produced this chart, which tracked Beck's weekly ratings since he signed on to Fox News in January, 2009. Note how the show, for weeks on end, often flirted with the 3 million viewer mark. But no more.

And do you see how Glenn Beck consistently posted its weakest numbers during the summer months last year? With the show's ratings heading south this spring, will the summer of 2010 set even more ratings lows for the star talker?