On New Year’s Eve in 2007, Kamala Harris, then the district attorney of San Francisco, prepared to spend the holiday more than a thousand miles away from her native California. She had flown to Iowa for the first time, touching down in Des Moines during one of the wettest winters on record.
Ms. Harris turned up in a dingy campaign field office, wearing a puffy coat and boots. Near a tangle of power cords, someone had propped an “African Americans for Obama” poster against a wall. In the midst of that bleak Midwestern winter, Ms. Harris was there to knock on doors for Barack Obama, the junior senator from Illinois mounting a long-shot bid for the presidency.
“To be here is worth 1,000 Champagne bottles and firecrackers,” Ms. Harris told a reporter on New Year’s Day, surrounded by campaign detritus. “It’s equal to that, in terms of the thrill, the excitement and the promise for tomorrow.”
Supporting Mr. Obama was a political risk. Ms. Harris was one of the rare Californians holding elected office — and one of few in the Democratic Party writ large — to endorse him for the presidency. Most of the party’s institutional heft had been thrown behind Hillary Clinton, a senator from New York who had a powerful surrogate in her husband, former President Bill Clinton.
But Ms. Harris’s early bet paid off, and Mr. Obama has never forgotten it.
“She was just a rock-solid supporter of the president at a time the entire political establishment was not with him,” said Buffy Wicks, a California State Assembly member who was the 32nd person hired by Mr. Obama’s campaign. “She set aside significant time and energy to help get him elected, and that was greatly appreciated by him.”
On Tuesday evening at the Democratic National Convention, Mr. Obama will return the favor, delivering a speech he has been working on for at least three months, according to a person briefed on his preparations. Of course, he has in recent weeks retooled his remarks to fit a different nominee — but one who has aligned herself politically with him for two decades. The two share a view of politics that is defined by offering economic and social opportunities to people who have been historically cut off from them.
“It is a sense that politics is not about you,” said Dan Pfeiffer, who served as a senior adviser to Mr. Obama. “It’s about building a movement.”
After Mr. Obama clinched the Democratic presidential nomination in June 2008 and the presidency that November, Ms. Harris surfed a tide of flattering headlines and favorable comparisons to the party’s new leader. She declared a run for attorney general of California shortly after Mr. Obama was sworn in.
“There’s an Obama halo that, you know, he shined the light on her,” said Brian Brokaw, who ran her campaign for attorney general. “The comparisons came naturally and fast.”
Back then, Mr. Obama thought she was “smart as hell,” he would remark to his aides, praising her abilities as a political performer and her toughness as she waged her unlikely campaign to become California’s top law enforcement official. Still, he had unquestionably become the bigger star, and her support of his campaign took her only so far.
He did not endorse her until after she won the primary race. For a president to support a candidate in a down-ballot state race would have been unusual, but even after winning, she had to ask for the endorsement, Mr. Brokaw recalled.
On another occasion, Mr. Brokaw added, Ms. Harris tried to attend an event headlined by Mr. Obama in San Francisco only to be turned away at the door for not having the correct invitation. She told the police guarding the event that she was the district attorney, and they let her in to see the president.
Still, when Ms. Harris visited the White House, she was received “with open arms” by Mr. Obama, recalled Ms. Wicks, who worked in the Obama administration as deputy director of the White House office of public engagement.
“They met, they clicked and they have over the years developed a very close friendship,” said Valerie Jarrett, one of Mr. Obama’s closest friends and a senior adviser to him when he was president.
Their relationship dates back to 2004, when Ms. Harris helped host a fund-raiser for Mr. Obama’s Senate run in a San Francisco hotel ballroom. Ms. Jarrett added that Mr. Obama and Ms. Harris quickly bonded over their cultural backgrounds, finding comforting commonalities with each other in a political world dominated by white politicians.
Both are mixed-race Americans, born to parents who came from different parts of the world, a shared experience that led them both “to believe you can find something in common with just about anybody.”
In 2007 and 2008, Ms. Harris, the daughter of an Indian scientist and a Jamaican economics professor, became not just a powerful surrogate for Mr. Obama’s policies but also an ambassador for his cultural background, explaining the complexities of his identity to voters who had never contemplated a presidential candidate like him before.
“A lot of us tend to oversimplify political labels,” Ms. Harris said in 2007. “He’s much more interesting and complex than those normal categories.”
Their shared brand of politics is based on the idea that the ascent of people with racial and cultural backgrounds like theirs is a testament to the country’s strengths, rather than a rejection of its values.
They have spent their careers making the case to a predominantly white country that “a skinny kid with a funny name,” as Mr. Obama called himself as a Senate candidate at the 2004 Democratic convention, and Ms. Harris, “a daughter of Oakland” raised by a single mother, could help Americans build cultural bridges to one another and transcend political differences.
At the beginning of their political relationship, Ms. Harris argued that Mr. Obama’s background — his mother was a white Kansan and his father was from Kenya — was an asset, the sort of identity that a growing number of Americans would regard not as a threat to the status quo but as a welcome feature of living in a diverse democracy.
Their relationship has been defined by their mutually beneficial political trajectories, according to people who know them both. But Mr. Obama also apparently saw something else. In 2013, he found himself at the center of a media storm for praising Ms. Harris’s physical appearance at a fund-raiser in California.
“You have to be careful to, first of all, say she is brilliant and she is dedicated and she is tough, and she is exactly what you’d want in anybody who is administering the law, and making sure that everybody is getting a fair shake,” Mr. Obama said at the time. “She also happens to be, by far, the best-looking attorney general in the country.”
Mr. Obama had not known immediately that he had made a mistake, according to two former White House aides who worked for him at the time. But one of them, who spoke on the condition of anonymity to describe the delicate situation that followed, remembered wishing “for the earth to swallow me whole” to avoid questions from reporters after Mr. Obama made the comment. Mr. Obama later apologized to Ms. Harris. She did not express any anger or annoyance about the comment to the Obama camp, according to the former White House aide.
“She made it clear he was a friend trying to compliment a friend,” said Gil Durán, who worked as an aide to Ms. Harris when she was attorney general.
The episode did no real harm to their relationship. In fact, Ms. Harris was floated as a possible replacement for Eric H. Holder Jr. in 2014 as he prepared to leave his post as U.S. attorney general. Mr. Holder called and asked if she was interested, according to her 2019 memoir, “The Truths We Hold.” She made a list of pros and cons on a legal pad, ultimately deciding against pursuing the position: “When it came to the work that mattered most, I wasn’t finished yet.”
Over regular phone calls and occasional meals, Mr. Obama’s involvement in her career ramped up during Ms. Harris’s vice presidency. When things were rocky, he offered support and suggestions.
Over a year ago, one of his former advisers, Stephanie Cutter, began working with Ms. Harris. Ms. Cutter’s role in the 2008 presidential campaign was to shape Michelle Obama’s public image — and to help her avoid unseen pitfalls that came with being the first Black spouse of the first Black presidential candidate. Ms. Cutter is now a senior adviser on Ms. Harris’s campaign.
When President Biden made the decision to end his 2024 campaign and informed the vice president, she had a round of calls to make. The first several went to family members, including Doug Emhoff, her husband. But out of more than 100 people the vice president spoke with that day, Mr. Obama was third or fourth on her list, according to a person briefed on her calls.
Since then, Mr. Obama has helped advise her on political messaging and personnel, including her selection of a running mate. And it is no accident that Ms. Harris’s campaign has focused on the ideas of joy and freedom, 16 years after Mr. Obama’s campaign promised hope and a new start.
“They’re both really joyful, optimistic spirits,” said Ms. Jarrett, who flew with Mr. Obama from Martha’s Vineyard to the convention in Chicago on Monday afternoon. “That’s something they were born with. That hasn’t changed over time.”
Kitty Bennett contributed research.