The New York Times' David Carr (9/20/10) compares involvement by media figures in politics–exemplified by CNBC's Rick Santelli and various Fox News figures fueling the Tea Party movement, and Jon Stewart and Stephen Colbert's dueling answer rallies to said movement–to "a football game where the reporters and commentators, bored by the feckless proceedings on the field, suddenly poured out of the press box and took over the game." Writes Carr: "In politics, it seems as if the media is intent on not just keeping score but also calling plays."
Regardless of what one thinks of any particular media figure's political advocacy, it should be remembered–in a nation that was basically imagined into existence by a political commentator named Thomas Paine–that there is nothing at all unusual or alarming about people writing and talking about politics in the hopes of affecting the course of political life. Indeed, that's the most obvious reason to become a political journalist, and the assumed role of journalism that underlies the First Amendment. It's only the corporate media tradition of trying to conceal the political opinions of journalists in the hopes of marketing the broadest possible audience to advertisers that makes it seem natural to think of journalists as people who ought to confine themselves to "keeping score" rather than getting directly involved in the sport of politics.