The participants in the reëntry program—which Simon says her more conventional colleagues called “hug-a-thug”—were mostly drug dealers, motivated by economic necessity. Simon said, “She understood that we actually could, slowly but surely, get them out of systems by just focussing on basic needs.” The program was small, and difficult enough to complete that one public defender complained to me that it often amounted to an easy felony conviction for the D.A. But it was novel, and it was not required of the D.A. politically. As attorney general, Harris sought to take the program statewide, starting with Los Angeles County.

Harris’s version of progress depends not on a system-wide overhaul but on a deliberate, iterative approach—you try something, go back, tweak it, try again. This approach befitted the offices she sought, and the large and politically heterogeneous state she represented. Popkin, the political scientist, told me, “As an attorney general, to get anything done between Black Lives Matter and the police, you have to be really good at not overdoing it one way or the other. You’re the ref, and you’ve got to make both coaches equally unhappy.” In the current election, though, many voters are uninterested in compromise. “You’ve earned this problem,” Popkin continued. “You’ve been cautious all along, and in a Presidential campaign people want bold. She had to be cautious to get big, and now she wants to go farther. What got you to the Senate won’t get you to the White House.”

From a young age, Harris says, she has felt the weight of what she represents; that awareness has made her almost unnaturally self-controlled. “I know that when I make decisions it will impact a lot of people,” she told me. “That’s where I’m not going to be modest. I also know that when I say something there will be a lot of people that will trust that I will have thought through what I’ve said. Mrs. Shelton, my second mother, and so many people in my life, they would often say, ‘Well, what does Kamala say about it?’ I know that there are people who count on me, and for that reason it is really important to me that I have and take into account all information, and if I was wrong about something, I don’t let pride associate. Because the consequence of what I do and what I say can be profound.” Her voice was quavering, and her eyes were filling. She swatted my arm. “You got me!” she chided.

In her memoir, Harris writes that she was “raised not to talk about myself”—such displays were considered narcissistic and vain. But, if you don’t want anyone else to define you, you had better define yourself. In June, several days after we met at Blue Bottle, Harris decided it was time to dispel lingering doubts (“I like her, but . . .”) that liberals harbored about her record as a prosecutor. She chose a predominantly black audience, at an event held by the South Carolina N.A.A.C.P.: the listeners who would be most receptive to a nuanced discussion of race and policing, and, perhaps, the people she most needed to win over.

As a prosecutor, Harris learned how to expose defendants and ferret out lies. She also learned to woo a jury. Nancy O’Malley, who was Harris’s supervisor in Alameda County and is now the district attorney there, says that she could take the most brutal, intricate case and make it accessible. “She had an authoritative, serious tone, but there was a softness about the way she presented the evidence,” O’Malley told me. “The jurors’ eyes were all wide open.”

Harris began her speech at the N.A.A.C.P. event, at a Baptist church in West Columbia, by praising the other speakers, the attendees, and “the ancestors.” She told the crowd, “My mother used to say, ‘You don’t let people tell you who you are. You tell them who you are.’ So that’s what I’m gonna do. That’s what I’m gonna do. Because let me be clear: self-appointed political commentators do not get to define who we are and what we believe.”

She had become a prosecutor, she said, in spite of her family’s skepticism, because she wanted to protect people and fix problems from inside the system. “I know and I knew then, prosecutors have not always done the work of justice,” she said. “Yet I knew the unilateral power prosecutors had with the stroke of a pen to make a decision about someone else’s life or death. . . . I knew that it made a difference to have the people making those decisions also be the ones who went to our church, had children in our schools, coached our Little League teams, and knew our neighborhoods.” To applause, she said, “I knew I had to be in those rooms, and that we always have to be in those rooms, especially and even when there aren’t many like us there.”

In the following weeks, as she travelled back and forth between South Carolina and Iowa, Harris built a case. Her background as a prosecutor was not a reason for defensiveness but a defining strength—an expression of the values she was raised with. When I asked Harris what she thought Trump’s greatest vulnerability was, she said, “His policies are weak. He has not come up with a meaningful policy on much of anything, from infrastructure to climate change. Look at his perspective on climate change—he’s talking about clean coal. Literally, there is a case to be made and to be prosecuted on this Administration’s policies.” She had gone after sexual predators and predatory lenders and perpetrators of fraud. Who better to take on Donald Trump? In speeches, she laid out Trump’s “rap sheet,” including “ten counts of obstruction of justice.” (In a looser moment, she joked, “He claims to be the best President we’ve seen in a generation. Well, I say, ‘Let’s call Barack Obama, ’cause that’s identity fraud.’ ”) The coolheaded incantation “Let’s speak truth” was replaced with a rousing alternative, “Let’s prosecute the case!”—a through-the-looking-glass version of “Lock her up” that unnerved some legal experts. Many Democratic candidates, including Harris, support impeaching Trump. In Iowa, she suggested a straightforward prosecution, saying, “I know predators, and we have a predator living in the White House.”

In late June, Harris had her chance to speak to the largest audience yet of the Democratic primary season, at the first debate, in Miami, which a record eighteen million people watched on television. Lily Adams, Harris’s director of communications, described the planning: “There’s this continuing question, What’s your background? Who are you? We were thinking, This is a huge opportunity to make a first impression.” The objectives were narrow. “One was to demonstrate strength and give a performance so that Democratic voters would say, ‘She’s who I want to put up against Trump,’ ” Adams said. “That’s the Kamala Harris from the hearings who has given such aggressive oversight to the Administration and spoken with moral clarity about all the damage they have done. You want to convey that. The second was, on any issue, talk about your priorities, this 3 A.M. agenda—for her to say, ‘What would be important to me as President are the issues that keep you up, that you worry about.’ ”