Imagine if the media devoted to the gun issue a fraction of the airtime and column inches lavished on David Petraeus and Paula Broadwell and Jill Kelley. The questions about how to grapple with our gun culture would be inescapable.

There was certainly a media agenda during the battle for civil rights in the late 1950s and 1960s. Television helped shine a spotlight on Alabama Gov. George Wallace and other Southern politicians who were fighting to preserve a segregationist society. News organizations were accused of being liberal, but they were on the right side of history in exposing practices that were fundamentally wrong. Rosa Parks’s refusal to move to the back of the bus would have been for naught had the media not made her a symbol of racial injustice.

In more subtle fashion, the media have led a national conversation about gay marriage, which as recently as 2004 was deemed politically unthinkable. Now it is legal in nine states, the last three of which adopted new laws in popular referenda last month. Again the press was accused of taking the liberal side, but sometimes that consisted of interviewing newly married gay and lesbian couples, who didn’t seem threatening to anyone. Whether the media changed the culture or lagged it, they were not missing in action.