Teneo has its headquarters on the forty-fifth floor of the former Citigroup Center tower in Midtown and employs more than 200 people in 13 cities, including Dubai, Hong Kong, and São Paolo. It describes its raison d’être as “integrated counsel for a borderless world,” offering investment banking, restructuring advice, and “business intelligence” on dealing with “global disruptors.” According to its website, Teneo has “advised on more than $525 billion of M&A transactions, served presidents and political leaders all over the globe, and counseled the leaders of many of the largest and most complex corporations in the world.”

From the beginning, Teneo resembled an outpost of Clintonland more than an independent entity. Clinton and Blair came on as paid advisers. One of the firm’s managing directors is the former CEO of the horse-racing and gambling empire belonging to the family of Belinda Stronach, a Canadian former politician whose friendship with Clinton has been the subject of considerable speculation. Nancy Hernreich Bowen, director of Oval Office operations under Clinton, works in the Hong Kong office. Last year, Abedin signed on with the firm, providing, in her own words, “strategic advice and consulting services to the firm’s management team” as well as helping to “organize a major annual firm event.” (The Senate Judiciary Committee is investigating whether her work conflicted with her position as a paid State Department consultant.)

A number of key Teneo clients were also closely involved with Clinton’s charitable work. One month before the Rockefeller Foundation presented Clinton with an award for philanthropy, it gave Teneo a $3.4 million contract to propose “tangible solutions to global problems.” Another early client was Coca-Cola, which helped build the distribution system for medicine in Tanzania, Mozambique, and Ghana, for a CGI project. Band has served on Coca-Cola’s international advisory board, and a former Coke CEO, Donald Keough, chairs the boutique investment bank Allen & Co., which holds a financial interest in Teneo. Other Teneo clients include the big hospital chain Tenet (which is a lead partner in the new Clinton Health Matters Initiative) and UBS Americas (which launched a Small Business Advisory Program with the foundation). “What Doug has ended up doing, if you sort of step back and look at it, is that he has met some of the most influential people in the world through President Clinton and has ended up building a business dealing with and helping those people,” says the Clinton friend.

Of course, it was only natural that Band would tap his existing network. What is striking is the extent to which Teneo’s business model depends on his relationship with Clinton. Band’s former White House colleague says Teneo is essentially a p.r. firm that is able to charge above-market rates because it persuades executives that Band and the ties he brings are an essential service. “If they were paying $25,000 or $40,000 a month for p.r., then $100,000 a month, from the eyes of the CEO, ... it’s not going to crush him,” says the former colleague. (According to The New York Times, Teneo’s monthly fees can be as high as $250,000.) The longtime Clinton associate says that Band’s pitch to clients was that he was “able to fly around [with Clinton] and decide who flies around with him. ... The whole thing is resting on his access.”

A few months into Teneo’s existence, it began to present difficulties for the Clintons. In late 2011, it emerged that the company had been paid $125,000 per month in consulting fees by MF Global, the brokerage firm that lost $600 million of its investors’ money. There were reports that Hillary Clinton was upset about potential conflicts between Teneo’s overseas clients and her work as secretary of state. In February 2012, Bill Clinton’s office announced that he would no longer take payment from the firm. The page listing an “advisory board” headed by Clinton and Blair vanished from its website.

Bill Clinton was having deeper misgivings, say several people close to the situation. It was becoming difficult to ignore how aggressively Band was working his Clinton connections on Teneo’s behalf. Some of its biggest clients, such as Dow Chemical, were the same companies whose CEOs Band had done special favors for at CGI: getting them on stage with Clinton, relaxing the background checks for credentials, or providing slots in the photo line. In Teneo’s first year, anyone on the payroll or client list got full access to CGI, plus coveted backstage passes, according to someone closely involved in CGI. To obtain extra credentials, Band would make a call and the tickets would be FedEx-ed overnight. At CGI’s September 2011 summit in New York, two suites were reserved upstairs from the conference at the New York Sheraton for meetings with top donors and heads of state. But when the Chinese ambassador was brought upstairs for a meeting, CGI officials found both suites occupied—one by Band, one by Kelly, who were pitching potential clients. After that, Teneo lost its special access.

A month later, Clinton got a firsthand taste of Teneo’s promotional style. He had been invited to the Global Irish Economic Forum in Dublin by Irish Prime Minister Enda Kenny. Declan Kelly was also on the speaking schedule, and, according to one person with close knowledge of the event, Kelly’s remarks suggested that it was Teneo that had brought Clinton to Ireland. Clinton went ashen, according to this person, and later exploded in anger, railing that Kelly had embarrassed him in front of the prime minister. (Kelly did not respond to a request to comment.)

At around the same time, Clinton was receiving reports of just how boldly Band had been offering his consulting services to major donors to CGI or the foundation, according to two people close to the foundation. According to these people, Band’s pitch left the donors with the distinct impression that Clinton had encouraged the donors to avail themselves of Band’s services. Among the people who Band may have approached, Clinton was told, was media mogul Haim Saban, who has donated more than $10 million to the foundation. Through a spokesman, Saban denied that Band had made such a pitch. However, one person close to the foundation says that Band’s consulting for donors came to the fore in a 2011 audit of the foundation’s finances by a New York law firm. The second person close to the foundation says that one major donor complained directly to Clinton that he had been writing large checks to Band and was upset that his access to Clinton had decreased. “The president was furious.”

As Band’s relationship with Clinton deteriorated, he sought public ways to demonstrate that nothing had changed. In September 2011, the White House made overtures to secure Clinton’s participation in Obama’s reelection campaign. The first step, it was deemed, would be a round of golf. The initial thinking in the White House was to include Joe Biden, an old Clinton chum.

Band was involved in the planning, and he sensed an opportunity to raise his profile. According to people aware of the discussions, he started talking up a different arrangement: a game with the two presidents, Bill Daley (Obama’s then–chief of staff and a former Clinton Cabinet member) and himself. The proposal had a certain symmetry—the current president, the former president, and their top aides. Daley expressed interest, and the plan acquired its own momentum. The White House wasn’t happy, but it knew that Band still controlled access to Clinton. The upshot was that the vice president was bounced and Band got into the frame. (Daley told me he was unaware of any plotting to exclude Biden.) “Once he got Daley on board, it was just a matter of time before he could get to pushing out the vice president,” says one person close to the negotiations. “Doug was on a separate track.” The round was held, to much media fanfare, on a muggy Saturday on the links at Andrews Air Force Base.

Clinton was thrilled to find that the Obama team wanted to deploy him to full advantage. Throughout the campaign, however, Band was unwilling to let bygones be bygones. He demanded that the Obama team help pay off Hillary’s 2008 campaign debt as a condition of Bill’s assistance. Though he had no campaign experience, he objected to the locations that the Obama campaign wanted Clinton to visit. He insisted that Clinton spend more time in Florida (Band’s home state), rather than being dispatched to, say, Minnesota. He tussled with Obama’s people about who would speak first or second in joint appearances. Band’s relations with Obama strategist David Plouffe were “disastrous,” says one high-ranking Democratic source. “Doug made everything harder than it needed to be,” says the source. “Dealing with the Clinton world always had something to do with what Doug wanted. You had to go through a big process and suck up to Doug, and he had to tell you for a long time how stupid you were.”

Eventually, the source says, a couple of senior campaign officials told Clinton about the problem. “Most people in that role ... usually reflect [their] boss. Doug did not reflect his boss. Clinton is easy to work with and likes to get stuff done,” says the source. “I would be surprised if Clinton had a full assessment of how difficult Doug was.” For a while, Band was “still trying to be part of things,” the source adds. Eventually, though, his gatekeeper role was passed to other Clinton aides. Meanwhile, Band’s reputation inside the Obama campaign became outright toxic after The New Yorker reported that he planned to vote for Mitt Romney, which Band denied.

By the election’s end, Band’s standing in Clintonland had visibly declined. In January, he went off the payroll of Clinton’s personal office, though not without negotiations about whether he would be allowed to keep his valuable presidentclinton.com e-mail address. His role within CGI was also the subject of dispute. The foundation stopped paying him in 2011, but he remained on CGI’s advisory board. Tensions simmered between Band and Chelsea Clinton, who has assumed a more active role in what is now officially the Bill, Hillary, and Chelsea Clinton Foundation. Chelsea, who once felt only fondness for Band as a trusted member of her family’s circle, came to worry that the overlap between the foundation and Band’s business interests could backfire on the Clintons. Podesta, who came in to put the foundation’s house in order in 2011, says, of the grumbling about Band: “There was a kind of capacity issue. You can’t do everything.”

Meanwhile, Hillary’s adoption of the foundation as a temporary perch this year has left even less space for Band. “Hillary and Chelsea’s view was, Look, if you’re going to work for the foundation you should work for the foundation and nothing else,” says the Clinton friend. “But for Doug, it was hard, because he’s been involved in it from the beginning. It was, Yeah, come on man, I can do both.” He added, “I don’t think [Chelsea] was wrong. In the past, no one would care what he was doing, dealing with all those people. Today, the last thing anyone wants is noise.”

Bill Clinton tried to smooth things over in a March 2012 statement, writing, “I couldn’t have accomplished half of what I have in my post presidency without Doug Band.” (The New York Times reported that Band helped edit the statement.) Likewise, Hillary’s camp has struck a conciliatory tone. “While she recognizes that after years of putting her family first, Doug’s family must be his priority, she appreciates the support he continues to provide to the president and the Foundation,” one long-term Hillary adviser wrote in an e-mail.

These days, Clinton and Band now speak only every couple of months when they run into each other at events, such as a fund-raiser Band co-hosted for Terry McAuliffe in February. “It’s gone from being a surrogate son relationship to an awkward thickness when they’re in the room together,” says one person with close knowledge of the relationship who has witnessed this dynamic firsthand. “It’s like when your wife cheats on you, and after the divorce, you have to see them at the friend’s wedding or at the supermarket. There’s a strangeness to it.”

This person says the two men have had “tense conversations” and that Clinton is deeply pained by his aide’s efforts to capitalize on their relationship. Others close to Clinton have also observed a distinct chill between them. As always, however, Clinton detests confrontation. “It’s hard for him,” says the person with close knowledge of the relationship. “At some points in his career, he spent more time with Doug than he did with his own wife. They knew everything about each other, he loved seeing Doug’s family, loved the stories and the antics. And then, to have it turn into ‘your adoptive son has run away.’ ... It burns him internally, and his way to deal with it is not to talk about it.”

Of course, it is very much in Band’s interest to downplay any animosity. “Doug’s currency is as a Clinton guy,” says Band’s former White House colleague. “Doug has developed a network that stands on his own—the number of people who know him around town and around Washington and around the world is pretty big. But what they think of him is as a person who knows President Clinton and is close to President Clinton.” Band and Teneo now have a large payroll riding on that image.

Band’s friends say he has entered a new chapter of his life—less concerned with politics and more focused on Max and Sophie, whom he speaks about in near-reverential terms. In late June, he added more room for his growing family (he and Lily are expecting their third child), purchasing another eighth-floor unit in the Essex House for $1.5 million. “There’s good in the world that he has done, and now his family and his friends are his real focus,” says Sobelman. “When we talk, it’s more: How’s work? It’s going well. Now, let’s talk football.” Band is also teaching an occasional class at New York University where he is billed as “the Honorable Doug Band”; the syllabus kicks off with a Politico piece describing him as “by far [Clinton’s] most powerful aide.”

The ultimate measure of Band’s place in Clintonland will come if Hillary runs for president. Some in Clinton circles predict that Band would, for once, remain outside the action, doing no more than fund-raising. “There are a lot of people jockeying for position and Doug is a little bit on the sidelines,” says the former White House colleague. “It’s good to have someone around Clinton who is a little less ‘us against them,’ a little more ‘we’re all in this together.’ ” But others believe Band would be right back at Clinton’s side if given the chance, despite all that has come between them. “You never really leave ... because you don’t want to,” says Begala. “I’m sure if the bell rings again, Doug will come running.”

Alec MacGillis is a senior editor at The New Republic.