When Kamala D. Harris launched her campaign for the 2020 Democratic presidential nomination in January, it seemed that the senator from California might be the one in this crowded field who had it all: experience, charisma and the exciting potential to make history as the first African American and Asian woman to sit in the Oval Office.

She has done a lot of things right since then. Harris has methodically laid out proposals, many of them bold, on teacher salaries, equal pay for men and women, stricter gun control, immigration and taxes. Harris has also assembled a top-notch campaign team and racked up important endorsements in the early primary states.

But as her leading rivals have come more sharply into focus in the early months of this presidential preseason, Harris has failed to make all of this add up to a clear definition of why she is running or what kind of president she would be.

In Senate hearing rooms, Harris’s prosecutorial directness makes her a standout, notably in her recent cross-examination of Attorney General William P. Barr when he appeared before the Judiciary Committee. But as a campaigner, she comes off as cautious and diffident, a criticism that has followed her throughout her political career.

Harris consistently ranks among the top handful of contenders in the polls, but her numbers have not moved upward. When her own home state held its Democratic convention earlier this month in San Francisco, Harris seemed to almost disappear under a wave of enthusiasm for the buoyant candidacy of Sen. Elizabeth Warren (D-Mass.).

Sen. Kamala Harris speaks to supporters at a campaign event in Columbia, S.C., on June 21. (Melina Mara/The Washington Post)

Democratic voters often say they want to like her but they haven’t been able to figure her out.

Tiffany Gamble, a 30-year-old stay-at-home mom, was a first-time delegate to the South Carolina Democratic convention on Saturday, where 22 Democratic candidates spoke. It was a warm-up to this week’s first debates in Miami, where Harris will share the stage with candidates including former vice president Joe Biden and Sen. Bernie Sanders (I-Vt.), who currently lead the polls.

Gamble said she is intrigued by Harris and excited by the possibility of a female president. But she also thinks Harris needs to “soften up a little bit and let people in a little bit — she’s [all] business. And if she could just show her personal side, I think she’d be amazing.”

In other words, what has been missing from Harris’s campaign is more of Harris herself.

The California senator has also been hearing that message privately from some of her key supporters, and it seems to be getting through. In back-to-back events over the weekend here, Harris spent less of her time talking about her plans and more of it explaining why she is the right person to turn them into reality.

At Saturday’s convention, Harris caused a sensation, and not just because a local high school’s drum line heralded her arrival down an ­escalator.

Where she has sometimes been on the defensive about her record as a former district attorney and state attorney general, it was the bona fide she touted as she laid out a fiery bill of particulars against President Trump.

“I know how to take on predators,” she said, to ecstatic cheers from the delegates. “So let me tell you, we need somebody on our stage when it comes time for that general election who knows how to recognize a rap sheet when they see it and prosecute the case.”

About an hour later, at a forum put on by the political arm of Planned Parenthood, Harris brought the audience to silence as she shared raw childhood memories of racial discrimination. She recalled how it hurt to see people “looking down on” her mother, a medical researcher, “assuming that she was somebody’s housekeeper and treating her like she was a substandard person because of assumptions of who she is based on how she looks.”

Harris does not deny that all of this marks a new, a necessary — and, yes, an uncomfortable — turn for her.

“It’s in me. Everything you heard today is in me,” Harris told me Saturday. But she acknowledged: “It doesn’t come naturally to me to wax on about who I am.”

“Part of it is I’m learning I should not assume that people know the relevance of the experience I’ve had,” she added. “I’m realizing more that maybe I need to show the math.”

Harris says that campaigning for president is “not a static process,” and she is right. One of the qualities that distinguish successful candidates from those who are not is an ability to recognize their own vulnerabilities and weaknesses and to improve their ability to connect with voters.

For Harris, that means stepping out of her comfort zone. She has shown she can do it, and she will have to stay there, if the early promise of her candidacy is to become a reality.