It’s her first event of the day—and not yet 11 in the morning—but already Chelsea Clinton looks tired: There’s a puffiness under her blue eyes and a heaviness to her smile. Taking the stage at the Hillary for America headquarters in Milwaukee, she grabs a stool. “Please know I’m sitting because I’m pregnant,” she assures the roomful of supporters, stroking her swollen belly. “It is not at all a reflection on my gratitude for you all being here or my enthusiasm for my mom’s campaign.”

Wisconsin’s April 5 primary is less than two weeks away, and for the next 20 minutes, Chelsea makes a case for why her mom is the most qualified candidate—the only candidate, really—for the job of president. She speaks slowly and deliberately, her voice low and modulated. After weeks of hard campaigning, she has grown slightly hoarse. But otherwise there are no rough edges to her. No seams. No rambling or verbal filler. Like Hillary, Chelsea is neither an inspirational nor a motivational speaker. But her soothing aspect is strangely compelling, like that of a meditation guide or a priest.

After her remarks, Chelsea makes her way to a side room where a gaggle of reporters hovers. This is the campaign chore she has always liked least, having long had an uneasy relationship with the media. In this way, too, she is very much her mother’s child. Methodical, deliberate, cautious, detail-oriented, and disciplined, she tries to keep an iron grip on her own narrative. Journalists pose a constant threat to that control.

Media access to Chelsea’s inner circle is meticulously managed. Asked even the most basic questions, her friends and colleagues tread cautiously. At times, their stories sound eerily similar, right down to the phrasing. (Chelsea is so caring and devoted, two different women told me, that she makes you wonder whether you are, perhaps, her only friend.) No one talks out of school, in some cases because they’re loyal, in others because they fear being cast into the wilderness by the entire clan—which, as more than one person reminded me, includes the woman who may well be the next president of the United States.

The Milwaukee reporters lob questions of the sort that Chelsea encounters dozens of times a week—about Bernie Sanders, for example, and Latino voters. Then one intrepid young man tries a different approach. Noting that if Hillary is elected, the nation will have a first gentleman rather than a first lady, he asks, “Do you think your mother will have you as a stand-in hostess in that position?”

It’s an odd question, and Chelsea is clearly itching to smack it down. She has a job in New York, she reminds him, and a family of her own. (Maybe the guy missed all the tummy patting?) At a previous campaign stop, she says, someone asked whether she planned to move back into her old room in the East Wing. Chelsea seems both amused and exasperated by the notion. While she hopes to have the privilege of visiting her mother in the White House, she explains, that is as far as she intends to go. “My life,” she says, “will remain in New York.”

Such is the paradox of being Chelsea Clinton. The once and possibly future first daughter has always been mature and accomplished beyond her years. Now 36, she has a child at home and another on the way, three advanced degrees, one book to her name, and a second coming next year. She plays a high-profile role as vice chair of the family’s global philanthropic foundation. On the side, she teaches, writes, gives speeches, and sits on corporate and nonprofit boards.

Yet Chelsea remains in the public mind an appendage of her world-famous parents, always available to fulfill her duties as the consummate political daughter. It’s as if she’s still the curly-haired teenager who walked hand in hand with her mom and dad across the White House lawn, literally and figuratively holding the family together, after Bill’s televised admission of bad behavior with Monica Lewinsky.

Chelsea was 18 years old and a freshman at Stanford when the scandal engulfed her father’s presidency. The photos from the day after his mea culpa, August 18, 1998, are by far the most famous ever taken of her. No longer the gawky adolescent target of Saturday Night Live jokes but not yet her polished-to-perfection adult self, she radiated both stability and vulnerability.

This was the sort of crisis Bill and Hillary had been girding their daughter for from the start. One of the oft-told tales from Chelsea’s youth is how, at age 6, she took part in mock debates that her parents held around the kitchen table in preparation for her dad’s 1986 gubernatorial race. The goal was to get little Chelsea accustomed to people saying mean things about someone she loved. Over the course of a number of dinners, Hillary wrote in It Takes a Village, “she gradually gained mastery over her emotions.”

In a way typically reserved for political wives, Chelsea became a barometer for how worthy her fallen father was of forgiveness. She was confused and wounded and crushingly disappointed in him. But she knew what was expected of her: Control your emotions. Keep moving forward. She stood by her father and eventually forgave him, leaving the president so grateful, according to Clinton insiders, that he will spend the rest of his life making it up to her.

Chelsea is deep into her second Wisconsin rally, this one with several dozen supporters crammed into the sweltering offices of the Waukesha County Democratic Party, when a woman a few yards from the stage starts yelling, “Call 911!” The elderly gentleman next to her has gone pale and glassy-eyed and looks as though he is about to hit the floor—which he soon does. Low-grade bedlam erupts as people try to decide whether to move in and help or give the poor guy some air. Eventually, it is determined that he is suffering from heatstroke, and Chelsea assures the audience that all will be well. The man is moved to a cooler room.

Chelsea announces that she will have to come back another time for a Q&A, then wades into the crowd for hugs and selfies, many with supporters who have no clue how to take one. A short, beefy guy wearing a tight red T-shirt proclaiming him hot for hillary snuggles close for a photo. “That is one of my favorite T-shirts ever!,” Chelsea says. Through it all—the heat, the medical drama, the endless nodding and smiling and posing—her composure never falters.

Poised. This is the word used to describe Chelsea more often than any other. Friends praise her as thoughtful, genuine, gracious, hardworking, brilliant, passionate about her causes, and, as is de rigeur for famous people one is aiming to humanize, down-to-earth. But almost everyone at some point goes with poised, making her sound a bit like a beauty queen or a diplomat or the ballerina she was in her youth. Or maybe a politician.

Poised captures Chelsea’s persona in more than one way. Over the years, she has been repeatedly painted as being on the cusp of emerging from her parents’ shadow. Each time she begins a new venture—going off to Stanford, taking a job at NBC, joining the paid-speaking circuit—stories appear declaring it the moment Chelsea has at last come into her own. Which, each time, is both partly true and partly a feat that continues to elude her. Time and again she gets drawn back into her parents’ orbit, called to be her father’s right hand or her mother’s chief character witness.

Chelsea’s time at Stanford provided distance not only from her mom and dad but also from the whole political world. By her final year, however, she had enough credits to take several months off. And just like that, she slid back into the role of full-time first daughter. She alternated between helping with her mom’s Senate race and serving as de facto first lady for her father—traveling with him, attending state functions, and generally filling in while Hillary was on the campaign trail. (During the Middle East peace talks at Camp David, Chelsea was there to chat up the delegations during breaks.)

In the most-famous photos ever taken of her, Chelsea Clinton was seen as holding her family together during the Monica Lewinsky scandal. (Roberto Borea / AP)

After college, she headed to Oxford for graduate school and then went to work in the private sector—first as a consultant at McKinsey, then as a chemical-industry analyst on Wall Street. She has characterized these moves as an experiment to see whether she could care about priorities different from her parents’. They also allowed her to largely drop off the media’s radar.

But her mother’s 2008 presidential campaign prompted what turned out to be a defining choice, to publicly re-embrace the family brand. No question her mom needed her. There’s no one better suited to counter Hillary’s likability problem, to assure voters of the candidate’s softer, more relatable, more human side. Considering how close the two women are, Clinton insiders say, Chelsea’s decision was never in doubt.

Over the next few years, Chelsea continued her questing—picking up a second master’s degree and a doctorate, teaching at Columbia, launching a multifaith institute at NYU, even joining the ranks of the dreaded media—while becoming ever more immersed in her dad’s foundation, which in 2013 was renamed the Bill, Hillary & Chelsea Clinton Foundation.

And so here she is, barnstorming the country for her mom once more, this time while extremely pregnant and with a toddler back home in New York. “My travel schedule is more like a yo-yo this time,” she tells me after the Waukesha event. In 2008, she would hit the road for weeks at a time. “My schedule could follow the geography of primaries.” Now, she says, “my most important geography is being home with my daughter. So I try to never be gone for more than about three days at a time.” Being the perfect political daughter, it seems, only grows more complicated with age.

More than once, Chelsea has publicly expressed how “frustrating” it was for her to set out to blaze her own trail only to wind up following her parents down theirs. But to what extent this is the product of their neediness or hers is unclear, perhaps even to the Clintons.

It wasn’t just family loyalty that brought her back into the fold, after all. Being the “daughter of” comes with enormous perks. Chelsea may be smart and diligent, but that’s not the only reason she got a post at NYU or a $600,000-a-year gig at NBC. And, for Chelsea, the lure of operating on the world stage proved irresistible. “When you’ve seen the positive impact that can come from a life of public service and the kind of difference you can make on a large scale, it’s hard to move away from that,” Sara Auld, a friend of Chelsea’s from Stanford, told me.

Having abandoned the idea of forging a wholly independent path—becoming, say, the doctor she once planned to be—Chelsea has settled into a kind of limbo: pursuing projects of her own, even as the Clinton brand smooths the way, and maintaining a wide buffer of privacy while enjoying the influence and access her fame confers.

But having it both ways will get trickier if her mother wins in November. Every move she makes will face heightened scrutiny by her family’s political enemies and a media less inclined to keep their distance now that she is closer to 40 than 14.

Already, she has taken a few hits. At a January campaign stop, Chelsea accused Bernie Sanders of wanting to dismantle existing health-insurance programs. While technically true (Sanders supports a single-payer plan) and hardly unusual for campaign rhetoric, the attack was jeered by Democrats and Republicans alike as misleading. Pundits gave her a rare walloping, and the veteran media critic Jack Shafer lectured the entire Fourth Estate to stop treating her like a fragile flower in an article whose headline proclaimed, “Time for Chelsea Clinton’s Easy Ride to End.”

The Sanders tempest sparked more than just PR static. The conservative group Citizens United (an enduring Hillary antagonist) promptly sued to get hold of e-mails sent between Chelsea and her mom’s top aides while Hillary was secretary of state. Citizens United is searching for inappropriate links between the Clinton Foundation and the State Department during Hillary’s tenure. The group’s president, David Bossie, declared, “We want to see much more about what Chelsea Clinton was up to.”

Elsa Collins, another friend from Stanford, told me she has a fond memory of talking with President Clinton at Chelsea’s wedding, in which she served as a bridesmaid. “I asked her dad, ‘Do you have any good parenting tips?’ ” she said. “Her father said that he used to do this thing with Chelsea where they would start a story. She would write down the first paragraph of a fantasy story. If he was out of town traveling, he would come back from a trip, and he would write the second paragraph. She would write the third, and they would take turns going back and forth.” In the end, they would wind up with “a great story that they would read together.”

Collins offers this as an illustration of Bill and Hillary’s desire to “engage” with their young daughter while still “respecting her childhood.” It’s also a fitting metaphor for what it’s like to be Chelsea Clinton: to have parents who love and nurture you, who help you develop your talents and urge you to be the best you can be—but who loom so large that it remains impossible for you to write a story of your own.