Study of 'Daily Show': It's a lot like O'Reilly

Politics, government and the Bush administration's policies in Iraq accounted for about half of the show's content, making it quite similar to the focus of serious cable news shows, the study said. About 8 percent of the show's time is spent looking at the behavior of the press.

The show is actually making some very serious political commentary, "but they use humor to do it," Rosenstiel said.

With some stories in no way conducive to humor, "The Daily Show" ignores certain big events. The Minnesota bridge collapse wasn't mentioned on the show, and the Virginia Tech massacre was largely ignored, the study said.

And, of course, sometimes the news gives way to pure comedy. On a January day when traditional newscasts led with severe winter weather gripping much of the country, "Stewart began his show by pondering what drink would be best to wash down a Jimmy Dean pancake and sausage on a stick," the study said.

The verdict: Gatorade.

While Stewart aims most of his firepower at Republicans, the show is actually pretty balanced in its bookings, the study noted. Of the clearly partisan, 15 guests were conservative and 18 were liberal. Presumptive GOP presidential nominee John McCain was a guest on Wednesday's show.