Joseph R. Biden Jr. selected Senator Kamala Harris of California as his vice-presidential running mate on Tuesday, embracing a former rival who sharply criticized him in the Democratic primaries but emerged after ending her campaign as a vocal supporter of Mr. Biden and a prominent advocate of racial-justice legislation after the death of George Floyd in late May.
Ms. Harris, 55, is the first Black woman and the first person of Indian descent to be nominated for national office by a major party, and only the fourth woman in history to be chosen for one of their presidential tickets. She brings to the race a far more vigorous campaign style than Mr. Biden’s, including a gift for capturing moments of raw political electricity on the debate stage and elsewhere, and a personal identity and family story that many find inspiring.
Mr. Biden announced the selection over text message and in a follow-up email to supporters: “Joe Biden here. Big news: I’ve chosen Kamala Harris as my running mate. Together, with you, we’re going to beat Trump.’’
After her own presidential bid disintegrated last year, many Democrats regarded Ms. Harris as all but certain to attempt another run for the White House in the future. By choosing her as his political partner, Mr. Biden may well be anointing her as the de facto leader of the party in four or eight years.
A pragmatic moderate who spent most of her career as a prosecutor, Ms. Harris was seen throughout the vice-presidential search as among the safest choices available to Mr. Biden. She has been a reliable ally of the Democratic establishment, with flexible policy priorities that largely mirror Mr. Biden’s, and her supporters argued that she could reinforce Mr. Biden’s appeal to Black voters and women without stirring particularly vehement opposition on the right or left.
For all the complexity of Mr. Biden’s vice-presidential search, there is a certain foreordained quality to Ms. Harris’s nomination. She has been regarded as a rising figure in Democratic politics since around the turn of the century, and as a confident representative of the country’s multiracial future. Ms. Harris sought to capture that sense of destiny in her own presidential campaign, announcing her candidacy on Martin Luther King Day in 2019 and paying frequent homage to Shirley Chisholm, the first Black candidate to seek a major party’s nomination.
Throughout her rise, Ms. Harris has excited Democrats with a personal story that set her apart even in the diverse political melting pot that is California: she is the daughter of two immigrant academics, an Indian-American mother and a father from Jamaica. Ms. Harris was raised in Oakland and Berkeley, attended Howard University and pursued a career in criminal justice before becoming only the second Black woman ever elected to the Senate.
Still, Ms. Harris was far from a shoo-in for the role of Mr. Biden’s running mate, and some of Mr. Biden’s advisers harbored persistent reservations about her because of her unsteady performance as a presidential candidate and the finely staged ambush she mounted against Mr. Biden in the first debate of the primary season. Jill Biden, the former second lady, called Ms. Harris’s debate stage remarks a “punch to the gut” at a fund-raiser in March.
In the end, however, Mr. Biden may have come to see the panache Ms. Harris displayed in that debate — when she confronted him over his past opposition to busing as a means of integrating public schools — as more of a potential asset to his ticket than as a source of lingering grievance. Indeed, even in the bleaker periods of her presidential candidacy last year, Ms. Harris maintained an ability to excite Democratic voters with the imagined prospect of a debate-stage clash between her and President Trump.