David Axelrod David Axelrod (Nam Y. Huh / AP)

Reading NBC News’s announcement Tuesday that it was hiring David Axelrod, a top adviser to Barack Obama’s presidential campaigns, as a “senior political analyst,” I had a sinking feeling in my stomach: No wonder the American public increasingly mistrusts the news media. We are obliterating the line between the political players and the people who are supposed to act as commentators and referees.

NBC boasted in its news release about how “for nearly three decades Axelrod guided successful campaigns at every level on the ballot.” Once upon a time, that would have been a disqualification for a news organization. But now, NBC brags that Axelrod “will contribute frequently across all broadcasts and platforms.” And he won’t just be a “senior political analyst” for MSNBC, the broadcaster’s more ideological affiliate, but also for the NBC mothership.

Just a week ago, MSNBC’s Rachel Maddow introduced Robert Gibbs, the former Obama White House spokesman and campaign operative, as a new contributor. Politico reported that Gibbs would also appear on NBC News.

This trend is hardly new. It’s commonplace these days for television news operations to hire former political advisers or campaign operatives as analysts. Fox has a stable of them, including former George W. Bush aides Karl Rove and Dana Perino, former Arkansas governor Mike Huckabee and, until recently, that modern-day Edward R. Murrow, Sarah Palin. ABC News’s budding superstar is George Stephanopoulos, who has adapted so well to journalism that people forget he was once a top White House aide to President Bill Clinton.

You could argue that the Post’s Opinions team is doing something similar online with running commentary from three longtime campaign operatives — Republican Ed Rogers and Democrats Carter Eskew and Hilary Rosen — whom The Post has dubbed “The Insiders.” The trend everywhere in the news business is toward more openly, avowedly partisan commentary, and away from the plain vanilla, down-the-middle variety (which has biases of its own).

I was taught that there’s a dividing line between politics and journalism and that people wouldn’t trust the news media if they began to fuzz this boundary. And guess what? That bromide from a passing generation of newspaper editors and network executives was right.

David Ignatius writes a twice-a-week foreign affairs column and contributes to the PostPartisan blog.