Minutes after the College of Cardinals imposed a formal media blackout in reaction to a leak of its private pope-picking deliberations, the short and stocky reporter who broke the story stepped out of the Holy See’s press office wearing a wool hat pulled over his ears, a hooded raincoat and orange-framed glasses.

“I’m a little journalist,” Andrea Tornielli said, earnestly. “I have no power.”

This is not, in fact, true.

Tornielli, who writes for La Stampa and its church Web site, Vatican Insider, is considered the dean of the “Vaticanisti,” the curious class of reporters, historians and gadflies who interpret for laypeople the shadows on the Vatican walls. As the Catholic Church has begun the process to elect its next pope, these often publicly devout, if privately irreverent, men and women act as sound-bite-ready Sherpas for the about 5,000 accredited journalists who have flooded into Rome to cover the selection story.

At their best, the truly connected Vaticanisti deliver insightful, deeply reported analysis of what transpires at the height of the Catholic Church’s hierarchy. At their worst, they are emblematic of conspiracy-obsessed Italian journalism, using thin and sometimes imagined sourcing as a means to agenda-boosting ends, the divining of which have themselves become a pontifical parlor game.

Either way, the most influential Vaticanisti certainly seem to have an impact on the papal-picking process.

“They are not observers. They are players. And this is their big chance,” said the Rev. Thomas J. Reese, author of “Inside the Vatican” and a senior fellow at the Woodstock Theological Center at Georgetown University.

At times, the Vatican views the Vaticanisti as a threat on par with, say, Napoleon. In the days leading up to Benedict XVI’s resignation as pope, the Vatican press corps reported on the contents of a secret investigation conducted by three cardinals into a papal letter-leaking scandal. (That Italian judicial reporters, and not the Vaticanisti, broke the so-called VatiLeaks scandal has prompted its own category of conspiracy theorizing.)

The unsourced allegations in Italy’s La Repubblica daily — that there existed within the Vatican a “gay network of priests” — triggered a media firestorm, especially after they were disseminated to the English-speaking world by Britain’s Guardian newspaper. The outcry prompted the Vatican to state that “often unverified, unverifiable or completely false news stories, that cause serious damage to persons and institutions,” had replaced “the so-called powers, i.e., States,” which had “exerted pressures on the election of the Pope.”

The Vatican may prize secrecy, but it has proved especially prone to leaks. (At a Thursday briefing, Vatican spokesmen expressed frustration about the indiscretions and invited the reporters in the room to name the sources if they knew them.) What separates the Vaticanisti from one another is the accuracy of the gossip they publish.

“I don’t have a horse in this race or anyone I’m trying to defend or support with my articles,” said Tornielli, who in the past has said there is an anti-Catholic bias in the mainstream media. “I challenge anyone to find in my articles evidence that I’m on one side or the other. I’m just trying to describe things and the mechanisms of power as they are.”

The most-respected Vatican reporters agree.

John L. Allen Jr., a reporter for the National Catholic Reporter, is widely acknowledged as one of the sharpest and most wired American Vaticanista. (One measure of his all-star status is that Corriere della Sera, Italy’s paper of record, has included him on its roster of international heavy hitters for conclave season.) Allen said that because sourcing in Italian Vatican reports was thin to nonexistent to fantastical, a Vatican watcher learns which bylines to trust simply by seeing which predictions pan out. Tornielli, he said, has the goods.

Some of his colleagues also have proved themselves especially tapped in to Vatican thinking.

On a recent afternoon, the well-respected Sandro Magister of L’Espresso magazine parked his motorino in front of Pontifical Gregorian University. He was carrying a rolled-up newspaper, which had a front-page article by another noted Vaticanista, asserting that the pope had moved out his right-hand man, Georg Ganswein, for failing to detect the leaking of papal letters from right under his nose.

“It not true,” Magister said with a shrug. He said what he would report that evening on his obsessively read blog, Chiesa: Far from being pushed aside, Ganswein’s power had exponentially increased.

Magister was right. Ganswein soon received a promotion, and the Vatican has announced that he will live with the pope emeritus and eventually oversee the household of the new pontiff.

In a piece published Thursday, Magister went out on a limb and predicted that a North American, most probably Cardinal Timothy Dolan of New York or Cardinal Sean O’Malley of Boston, would be chosen as pope.

Both Tornielli and Magister are acknowledged as throwbacks to a golden age of Vatican reporting.

“This was the job that everyone wanted, because John Paul II was perceived as such a better story than what was going on in Italian government,” Allen said, rattling off a list of names of mostly retired Vatican reporters. But, he said, the rise of Silvio Berlusconi, the largest political personality since Mussolini, provided a new center of gravity. (Berlusconi was convicted Thursday of illegally publishing information obtained in wiretaps.)

Pope John Paul II’s decline in health, followed by the interesting but more esoteric story of Benedict, resulted in a drop-off in reporting talent. “The Vatican beat became like the junior varsity,” Allen said.

Like so much in the Vatican, the Vaticanisti tend to have an Italian-centric view when it comes to considering who will inherit the throne of St. Peter.

“Their focus is primarily on their guys,” said Allen, who added that there was some wisdom in this approach, given that Italians can claim the largest group of cardinals — a total of 28 — from any single country. “But it also distorts reality in a way,” he said, by putting too much emphasis on Italian turf wars that are not likely to influence the thinking of many of the cardinals from other parts of the world.

More so than the report that caused the media blackout, in which at least one cardinal broke his vow of secrecy by spilling to Tornielli, it was his report earlier in the week about the emergence of a papal ticket of Brazilian Cardinal Odilo Scherer, with Italian Cardinal Mauro Piacenza as his second in command, that caught the attention of insiders.

Piacenza, the Vatican’s head of clerics, is a highly conservative and controversial figure. He recently confounded many in the church with a letter to the mothers of priests, informing them that “every mother of a priest mysteriously becomes a ‘daughter of her son.’ ”

Several Vatican officials said they viewed Tornielli’s inclusion of Piacenza on the ticket as a poison pill of sorts, an effort by his sources to torpedo Scherer’s candidacy.

Tornielli protested that others had complained to him that his report unfairly boosted the Brazilian.

“This was an actual thing that cardinals were talking about,” Tornielli said of the purported ticket. “The thing I am very careful about is not allowing myself to be used by anyone.”