Still more casual was Marshall’s own commentary at the Talking Points Memo blog. He sarcastically reviewed Murkowski and Penney’s explanations for the sale: “Imagine that, a politically-wired Alaska moneyman wants the state’s junior senator to live next door to him. Who can question that?” He also sketched—in his most conversational, just-between-friends voice—“a series of very weird little details about Murkowski’s disclosure reports” that McGann had encountered during her reporting. “From an editor’s perspective, it was a bit hard to know how to treat this,” he wrote. “You don’t want to go too far out on a thin reed dealing with what could be mere errors in filling out the form.” (Ten days after McGann’s initial report, Murkowski announced that she would sell the land back to Penney.)

This odd admixture of reporter, columnist, tipster, and ombudsman—often wrapped into the same post—is central to TPM’s identity. Marshall values original reporting, but chasing scoops is not his only priority. Even if he and his colleagues decided to abandon original reporting entirely, TPM would probably still retain almost all of its audience. Marshall believes his role is to bring his readers the best journalistic efforts on a particular topic, even when those efforts have appeared in other publications.

There is occasional muttering that TPM fails to fully credit the newspapers whose reporting it aggregates. But Dean Calbreath, a reporter at The San Diego Union-Tribune, says that Marshall has “always been meticulous about crediting” his newspaper’s work. Calbreath and his colleagues have worked for two years on the interlocking scandals involving the now-jailed U.S. Representative Randy “Duke” Cunningham and his defense-contractor friends. TPM has often commented on the Union-Tribune’s coverage of those stories, and Calbreath says that TPM’s posts, even when they don’t appear to break news, still push the story forward. The site “provides reporters with sources that might not be at the top of our radar screen,” he says. “Being based in San Diego, I’m not a big reader of The Hill, for instance. But by reading TPM, I can have easy access to [The Hill’s] pertinent articles. The commentary at TPM, meanwhile, poses important questions that we might not have thought of on our own.”

Rood, of ABC News, says that he sometimes found TPM’s aggregation itch personally frustrating when he was on staff. TPM’s readership peaks in the late morning and midday—exactly when he felt a reporter should be on the phone with sources. But because of the readership pattern, it is during those hours that TPM reporters feel compelled to write new posts. “That’s not a complaint,” Rood says. “It’s just something that we had to work through. We were inventing this as we went along.”

Phrases like “inventing as we went along” come up often in conversations about Marshall. “Josh has been through so many self-made phases that no one could have predicted,” says Daniel Rodgers, a professor of history who supervised Marshall’s senior thesis at Princeton. Marshall arrived there in 1987 from southern California, where his father taught marine biology. (Marshall’s mother died in a car accident near their California home in 1981.)

In crafting his thesis, which concerned the nullification debate in Virginia in the early nineteenth century, Marshall “figured out how a historical argument works, and he figured out what sources he would need,” Rodgers says. “That’s not at all inevitable. Not every college senior who is excited about history makes that leap into effectively working with sources. If you like, there’s the thread between his college work and what he’s doing now—the interest in investigative reporting.”

David Glenn is a staff writer for The Chronicle of Higher Education.