Campaigns know how to play to different reporters’ interests. “I write a lot about education policy and health-care policy,” says Brownstein of the Los Angeles Times, “and if [the campaigns] have a point they want to make about the other guy on one of these subjects they’ll probably call me before they call somebody else. If they’re trying to sell something on national security they might call somebody else.” Says the New York Times’ Nagourney, “Let’s just say if a campaign knew that another candidate had an affair — the ultimate stereotype of opposition research — I don’t think they’d come to [the New York Times] with something like that.”

Yet journalists are not merely passive recipients of research. “More than reporters like to admit, a lot of the data flows by request,” says John Pitney, who was involved in opposition research for the RNC in the late ’80s and is now a professor of government at Claremont McKenna College in California. “That is, a reporter will call and ask, ‘What do you have on so and so?” The LA Times’ Brownstein admits almost as much. “If I believe that X candidate has said something in the past, but I can’t find it, I will call the research desk at the campaigns and ask do you know what John Kerry said about whatever,” says Brownstein. “I don’t see a problem with that, as long as you check the information, and they’re very good at providing [citations].”

Despite the overwhelming quantity of opposition research that flows in, competition keeps many reporters from unsubscribing from these email missives. “If they’re going to send that stuff to everybody else,” says CBS’s Bob Schieffer, “we want to make sure they’re sending it to us, too.” The New York Times’ Nagourney says that while he often can’t read everything he gets, he does “want to know everything that’s going on” and “doesn’t want to get caught by surprise.”

Competition also ensures a market for more selective leaks, whereby a campaign passes damaging material on the opponent to an individual reporter or to a select few media outlets. Jason Miner, head of opposition research for the DNC, says that in addition to the daily “rapid response” research they offer — largely, via email — “we also try to get new stories into the media blood stream. Those tend to be longer-term stories, working with individual reporters. We do a lot of that.” It can be enormously effective, he adds, since “reporters are always looking for exclusives.”

For example, in April, the New York Times and ABC News “obtained” a videotape of Kerry telling a Washington TV station in 1971 that he threw away his military medals to protest the Vietnam War. The tape seemed to contradict Kerry’s more recent claims to have thrown away just his ribbons, not the medals. In reporting on the tape, neither the Times nor ABC explained to their audiences how or from whom they “obtained” it or what agendas their source may have had. The Washington Post’s Dan Balz and Howard Kurtz reported the situation this way: “This was no accident, not in a campaign season in which opposition researchers are constantly trying to unearth damaging material about the Massachusetts Democrat and President Bush. In this case, copies of the tape were provided to two news organizations by the Republican National Committee, according to several media staff members familiar with the situation who, not surprisingly, said they could not be identified while discussing confidential sources.” Says John Pitney of Claremont McKenna College, most of these sorts of exchanges between opposition researchers and reporters — the selective leaks — happen “on the quiet.”

Liz Cox Barrett is a writer at CJR.