By Matthew Renda

(CN) — Presumptive Democratic presidential nominee Joe Biden selected California Senator Kamala Harris as his running mate Tuesday, upholding a debate promise to pick a woman to round out his ticket.

If Biden and Harris prove successful in their bid to unseat Republican incumbent President Donald Trump on Nov. 3, Harris would be the first female vice president — and the first vice president of color — in U.S. history.

Biden has also indicated that he believes Harris is ready to be president from day one, something he stressed was important as the former vice president turns 78 in November.

Biden pledged to select a woman as vice president this past March, after it became increasingly clear that the Democratic Party — which made racial diversity at the highest levels of the public and private sectors a major focus — would come down to a nomination battle between two older white men, Biden and Senator Bernie Sanders from Vermont.

Long the favorite, Harris brings diversity and youth to the Democratic ticket, both of which are seen as sorely needed on Biden’s ticket. Unlike others vying to be Biden’s running mate, Harris has extensive political experience, serving as California’s attorney general and then as the Golden State’s junior U.S. senator — becoming the first African American and the first Indian American to represent the state in the Senate. She defeated fellow Democrat Loretta Sanchez in 2016 to replace outgoing Senator Barbara Boxer.

Harris was never considered a lock for the ticket, partly because she and Biden locked horns early and often during the primary season. In the first debate, Harris attacked Biden for his opposition to school busing programs and for working with segregationists during his career. People with the Biden campaign have said the attack and Harris’s subsequent downplaying of it had created trust issues with Biden, who ranks personal rapport very high. Biden’s decision seems to indicate both parties have moved on from the earlier conflict.

Harris grew up in Oakland, California, the daughter of an Indian immigrant who left her homeland to pursue a degree in economics at UC Berkeley. Harris’ father was an economics professor at Stanford who immigrated to the United States from Jamaica.

After spending part of her childhood in Montreal, Harris returned to the United States to attend Howard University. She earned a law degree from UC Hastings School of Law.

She began her career as a prosecutor for the Alameda County District Attorney’s Office, but soon left to work at various positions in the San Francisco District Attorney’s Office.

Harris began her political career in 2003, becoming San Francisco’s DA by beating an incumbent. She was the top cop in San Francisco until she ran to become California’s top cop in 2011.

During her time as both DA and attorney general, Harris argued for the prosecution of parents of truant children, which earned the ire of progressives during the 2020 primaries, as reform of the criminal justice system and its orientation toward minority populations in America became a major issue.

Nonetheless, Harris garnered endorsements from a range of prominent Democratic politicians during her run including Boxer, Senator Dianne Feinstein and House Speaker Nancy Pelosi.