A few days after 18-year-old Mike Brown was gunned down in Ferguson, Missouri, White House officials enlisted an unusual source for on-the-ground intelligence amid the chaos and tear gas: the Rev. Al Sharpton, a fiery activist who became a household name by provoking rather than pacifying.

Sharpton—once such a pariah that Clinton administration officials rushed through their ribbon-cuttings in Harlem for fear he’d show up and force them to, gasp, shake his hand—arrived on the scene 72 hours after the shooting at the request of Brown’s grandfather, who had admired his advocacy on behalf of the family of slain Florida teen Trayvon Martin.

But if the old Al Sharpton would have parachuted into Ferguson to rile up the masses, the Obama-era Al Sharpton trod a more gingerly path to justice. Over the years, the 59-year-old former Brooklyn protest leader turned MSNBC talk-show host has embraced a new identity, one that reflects his evolution from agitator to insider with all that implies. In Ferguson, Sharpton established himself as a de facto contact and conduit for a jittery White House seeking to negotiate a middle ground between meddling and disengagement. “There’s a trust factor with The Rev from the Oval Office on down,” a White House official familiar with their dealings told me. “He gets it, and he’s got credibility in the community that nobody else has got. There’s really no one else out there who does what he does.”

And the White House, as the crisis following Brown’s death seemed to flare out of control, worked extensively behind the scenes to maximize The Rev’s doing what he does, using him as both a source of information and a go-between. After huddling with Brown’s family and local community leaders, Sharpton connected directly with White House adviser and First Friend Valerie Jarrett, vacationing in her condo in the exclusive Oak Bluffs section of Martha’s Vineyard, not far from where President Obama and his family were staying. Obama was “horrified” by the images he was seeing on TV, Jarrett told Sharpton, and proceeded to pepper him with questions as she collected information for the president: How bad was the violence? Was it being fueled by outside groups—and could Sharpton do anything to talk them down? What did the Brown family want the White House to do?

It was a heady consultation for Sharpton, who spent years on the outside dreaming of a place in the pantheon of the civil rights leaders he revered as a teenage street preacher in Brooklyn, and it’s an irony lost on no one that his rise to White House adviser has come thanks to Barack Obama, whose restrained personal style couldn’t be any more different from Sharpton’s. If anything, the Ferguson crisis has underscored Sharpton’s role as the national black leader Obama leans on most, a remarkable personal and political transformation for a man once regarded with suspicion and disdain by many in his own party. It’s a status made all the more surprising given that Obama, America’s first black president, ran on a platform of moving beyond the country’s painful racial divisions while Sharpton is the man who once defined those divisions for many Americans.

What brought them together, according to numerous sources I’ve spoken with about this over the years, is a shared commitment to racial justice, and a hardheaded pragmatism that has fueled their success. “He realized I wasn’t as irrational or as crazy as people thought,” Sharpton told me in an interview this week, and indeed Sharpton not only visits the White House frequently, he often texts or emails with senior Obama officials such as Jarrett and Attorney General Eric Holder, the first African American to hold that job and who, like Sharpton, views the Ferguson crisis as a pivotal one in Obama’s presidency.

“I’ve known Al since he was 12 years old, and he’s arrived at the level he always wanted to arrive at, which is gratifying,” the Rev. Jesse Jackson, a colleague and sometimes rival, told me. “He’s the man who’s the liaison to the White House, he’s the one who’s talking to the Justice Department.”

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To get where he is Sharpton not only shed 150 pounds but much of his old bullhorn-in-your-face-bombast. When we talked this week, he was preparing remarks to be delivered at the funeral for Mike Brown in Ferguson planned for Monday. Sharpton said his critics ignore just how much time and experience has matured him. “I’ve grown to appreciate different roles and different people, and I weigh words a little more [carefully] now. I’ve learned how to measure what I say,” he said. “Al Sharpton in 1986 was trying to be heard. I was a local guy and was like, ‘Y’all are ignoring us’... That’s not the case now.”

The many incarnations of Rev. Al Sharpton, 1988-2014. | AP Photo

Yet the old image is indelible. Three decades ago, the overweight, track-suited, medallion-bedecked Sharpton led a rally against a white-owned clothing store in Harlem that was subsequently burned to the ground by a deranged black protester, killing eight people. Around that time, he was convicted of defaming a white upstate New York prosecutor he falsely accused of raping black teenager Tawana Brawley in the 1980s, an infamous case that made him famous as the caricature of an inflammatory inner-city preacher immortalized by Tom Wolfe in Bonfire of the Vanities. Sharpton often, regrettably, played to type: During the 1991 Crown Heights riots in Brooklyn, Sharpton stoked black rage after a Hasidic Jewish driver killed a young boy with his car. At the child’s funeral, Sharpton railed against Jewish “diamond merchants” who bought their wares from apartheid South Africa, then ran down black kids in Brooklyn. There was his much-mocked stint as an FBI informer in the 1980s. There were poorly managed mayoral and presidential bids that ended in tatters, and in deep debt.

Sharpton’s mere presence remains an irritant to many white conservatives. When Sharpton this week denounced Ferguson officials for releasing surveillance footage of Brown roughing up a convenience store employee (he accused them of “smearing” Brown’s memory), Bill O’Reilly of Fox News ripped Sharpton as a “charlatan” and “race hustler” who only cared “about his own self-aggrandizement,” echoing dozens of similar critics over the years.

“How is it possible... that he carries so much tainted baggage from the past, yet still enjoys enormous pull with the political class?” was the question posed earlier this year by New York Post editorial writer Michael Goodwin, part of a Greek chorus of 50- and 60-something Gotham journalists determined to make sure Sharpton’s past isn’t lost in all the New Al talk.

“Why,” Goodwin asked, “isn’t he politically toxic?”

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Sharpton’s determination to reinvent himself has a lot to do with his rise, but he owes just as much to the unique symbiosis with the president, a relationship predicated less on personal friendship than on a colder assessment of mutual self-interest by two of the most powerful African Americans in the country. “He’s calculating ... he gets the game,” Sharpton recently told an associate when asked about why he’s bonded with Obama.

“The relationship evolved over time,” Sharpton explained to me. “I realized he was just a different kind of guy. ... He wasn’t going to be guided by emotions. He was not intimidated. There was no game you could play [with him]. The key for him was seeing that I wasn’t insincere, that I actually believed in the stuff I was talking about.”

Sharpton probably never would have gotten into Obama’s orbit if many of Obama’s 2008 campaign advisers had gotten their way. He was an early endorser of Obama’s—bucking other black power brokers like Harlem Rep. Charlie Rangel, who lined up behind Hillary Clinton—but the candidate’s mostly white leadership team was reluctant to let him into the fold. In his memoir The Audacity to Win, 2008 Obama campaign manager David Plouffe said Obama and his staff blew a gasket when they learned that Sharpton planned a pilgrimage to overwhelmingly white Iowa in the days leading up the critical caucus vote that year.

Obama got Sharpton on the phone and, in his genial way, began discussing the logistical challenges of a visit—maintaining all along that he wanted to make the visit happen. It took Sharpton a few minutes, but he got the message. “I called him back and said, ‘I’m not going,’” Sharpton told me. “He told people he never forgot that.”

Sharpton called it “the turning point” but of course, there was more to it than that. Obama, as president, needed a single, credible national spokesman on black issues, who was willing to catch flak from black critics as he navigated toward the political center—and he needed one whose name wasn’t Jesse Jackson.

Jackson, a former top aide to Martin Luther King Jr. and the first black leader to mount serious presidential campaigns (in 1984 and 1988), had leveraged his influence with Bill Clinton in the 1990s into status as a kind of president of Black America. But that wasn’t to be with Obama: Even though Jackson’s son Jesse Jr. had been close to Obama in Chicago, the older man never meshed with the Illinois upstart or his people (though Jackson told me he’s long been “one of the strongest of Obama’s strong supporters”).

But it was an under-the-breath, hot-mike comment Jackson made before a cable interview in July 2008 that defined his relationship with Obama; Jackson said he found Obama’s speeches at black churches so condescending he wanted to “cut his nuts off.” Obama’s team essentially wrote Jackson off after that, several members of the team told me. “Jesse wasn’t an option for us. He had gotten too old… and Obama completely eclipsed him—and then he had that hot-mic deal where [Jesse] said he wanted to cut [Obama’s] balls off,” a former top Obama adviser told me on condition of anonymity. “But there really was only one Jesse, and we needed to have someone to deal with in the African-American community, and Sharpton was the next best thing, so, yeah, we sort of helped build him up. ... Sharpton was the last guy standing.”

Eventually, Sharpton—often in consultation with Jarrett and Patrick Gaspard, the New York political operative who would go on to run the White House political office — carved out a unique role, defending Obama’s actions to black critics. In 2010, when the influential black radio host Tavis Smiley hit Obama for failing to articulate a “black agenda” on jobs, Sharpton shot back, calling Smiley’s charge “stupid” and accusing him of playing into the hands of Obama’s conservative critics.

“I don’t know how he’s managed to do it,” says Basil Smikle, a Democratic operative long active in Harlem politics and a veteran Sharpton watcher. “He’s an outsider’s insider or an insider’s outsider, depending on your perspective. He’s essentially covering for the president in Ferguson. ... His power has slowly and steadily supplanted that of other black leaders locally and nationally [and] the Obama victory provided a platform for him to alternate between agitator of institutions and defender of its leaders.”

Yet as Obama’s presidency enters its final two years, Sharpton—so often criticized for being a self-promoter—finds himself in the unusual position of being too close to a White House that seems to be losing power by the day. “We are now living in a world where Al Sharpton is considered a sellout,” joked one Sharpton ally.

Last year, around the time that Sharpton was participating in Obama’s celebration of the 50th anniversary of Martin Luther King Jr.’s “I Have a Dream” speech, black nationalist and former Harvard professor Cornel West tore into Obama and Sharpton for sanitizing King’s vision of economic and racial equality. “Brother Martin himself, I think, would’ve been turning over in his grave,” West told an interviewer at the time, adding: “We saw the coronation of the bona fide house negro of the Barack Obama plantation, our dear brother Al Sharpton.”

Sharpton dismisses the criticism, telling me, “I get hit as hard on the left as I do on the right,” but lately he’s been stepping back up the kind of activism that catapulted him to prominence in the first place. He’s taken a front-and-center role in leading the protests following the chokehold killing of a black Staten Island man at the hands of police—and will lead a huge rally in New York’s smallest and whitest borough on Saturday before appearing on NBC’s “Meet the Press” Sunday and heading back to Missouri for Michael Brown’s funeral.

At home, there are flashes of the old Sharpton. New York’s new mayor, Bill de Blasio, is a close ally who ran with his support in the 2013 Democratic primary (“People shouldn’t forget that I opposed a black candidate for de Blasio,” Sharpton reminded me, a reference to failed mayoral hopeful Bill Thompson). But that hasn’t stopped Sharpton from publicly confronting de Blasio or his police commissioner Bill Bratton in ways that would never wash with Obama and his staff. Earlier this month, Sharpton stunned a City Hall audience by saying the mayor’s biracial son Dante was a “candidate” for a police chokehold.

Sharpton has been much more circumspect with Obama. During his interactions with Jarrett over the Ferguson case, he urged the White House to turn up the heat on Missouri Gov. Jay Nixon, a Democrat, to appoint a special state prosecutor to replace St. Louis County Prosecutor Bob McCulloch—who has defended the actions of the highly militarized local cops and resisted calls for a rapidly expedited investigation. “We’re not going to get a fair investigation with that guy, he’s got to go,” Sharpton told Jarrett, according to one person familiar with the exchange. A spokeswoman for Jarrett, who has been in contact in with Nixon, declined to say if she had passed along Sharpton’s demand.

Sharpton, for his part, doesn’t plan to wait forever for backstage results: He told me he plans “a series of nonviolent protests to get McCullough out of the case within the next few weeks, when everything cools down a bit.”

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Whatever happens, it’s clear that Sharpton, the master of reinvention, will soon find himself at a crossroads. Even if he can lay claim to being the country’s most important black leader, what will that mean once the first black president leaves office—or when a newer generation of telegenic, Obama-inspired black leaders like Cory Booker demands their share of the spotlight?

When we talked, Sharpton told me he sees his model for success in the rear-view mirror, in the example set by Jesse Jackson.

“I never aspired to the local political fiefdom thing that a lot of people ascribed me to,” he said. “I saw myself as a guy who learned from Jesse Jackson how to do national civil rights. I wasn’t really interested in who was going to be the next district leader in Brooklyn. My ambitions were always a lot bigger than what my critics thought my ability was.” He goes on to list the lessons he learned from Jackson: “The Saturday rallies ... get your own TV show ... have a national organization”—lastly, make friends with a president.

“He was Clinton’s guy,” Sharpton bluntly told me, “and I’m with Obama.”

The meaning of that was clear this week in Ferguson, where Jackson, who was summoned to Missouri by local preachers, has spent as much time as Sharpton, but with little of the public attention after having been almost entirely marginalized by Obama’s team (Jackson confirmed to me he’s had little contact with administration officials since the Ferguson crisis began).

The relentless climber in Sharpton can’t help but feel proud of surpassing a role model, but he also sees a glimmer of his own future in Jackson’s fate.

“I think he’s now realized that he’s older now … And he realizes that I’ve come into my own and he’s got to deal with it,” Sharpton said of his complicated relationship with the older civil rights leader. “[The relationship is] respectful but it’s clearly not protégé-mentor. I still admire what he did, I just think that things pass on. I’m going to pass on—everybody has their day.”