She's already broken barriers, and now Kamala Harris could become the first Black woman to head a major party presidential ticket after President Joe Biden abruptly ended his reelection bid and endorsed her.Biden announced Sunday that he was stepping aside amid widespread concerns about the viability of his candidacy. Harris is the first woman, Black person or person of South Asian descent to serve as vice president. She joined the Biden ticket after a rocky and abbreviated run of her own for the 2020 Democratic presidential nomination.Biden said Sunday that deciding on Harris as vice president was “the best decision I've made.” He wrote on X, the social media platform formerly known as Twitter, that she had his full support and endorsement to run against Donald Trump for the presidency. “Democrats — it’s time to come together and beat Trump,” he said. “Let’s do this.”"I am honored to have the President’s endorsement and my intention is to earn and win this nomination," Harris said in a statement. "Over the past year, I have traveled across the country, talking with Americans about the clear choice in this momentous election. And that is what I will continue to do in the days and weeks ahead."Her nomination is hardly a sure thing. The party is split over whether Harris should ascend or there should be a quick “mini primary.”A recent poll from the AP-NORC Center for Public Affairs Research found that about 6 in 10 Democrats believe Harris would do a good job in the top slot. About 2 in 10 Democrats don’t believe she would, and another 2 in 10 say they don’t know enough to say.The poll showed that about 4 in 10 U.S. adults have a favorable opinion of Harris, whose name is pronounced “COMM-a-la,” while about half have an unfavorable opinion.A former prosecutor and U.S. senator from California, Harris will face doubters as she seeks to reassure the party she can win the presidency in November. Her first test will be at the Democratic convention in Chicago in August.Video above: Reactions to Kamala Harris potentially getting presidential nominationEven before Biden's endorsement, Harris was widely viewed as the favorite to replace him on the ticket. Actively campaigning in recent weeks, she's had a head start over potential challengers, including California Gov. Gavin Newsom, Michigan Gov. Gretchen Whitmer and Pennsylvania Gov. Josh Shapiro.Harris will seek to avoid the fate of Hubert Humphrey, who, as vice president, won the Democratic nomination in 1968 after President Lyndon Johnson declined to run for reelection amid national dissatisfaction over the Vietnam War. Humphrey lost that year to Republican Richard Nixon.Nixon resigned in 1974 during the Watergate scandal and was replaced by Vice President Gerald Ford. Ford never won a term of his own.Vice presidents are always in line to step into the top job if the president dies or is incapacitated. However, Harris has faced an unusual level of scrutiny because of Biden’s age. He was the oldest president in history, taking office at 78 and announcing his reelection bid at 81. Harris is 59.She addressed the question of succession in an interview with The Associated Press during a trip to Jakarta in September 2023.“Joe Biden is going to be fine, so that is not going to come to fruition,” she stated. “But let us also understand that every vice president — every vice president — understands that when they take the oath they must be very clear about the responsibility they may have to take over the job of being president.”"I'm no different."Kamala Harris' upbringing and start in California politicsHarris was born Oct. 20, 1964, in Oakland, California, to parents who met as civil rights activists. Her hometown and nearby Berkeley were at the heart of the racial and social justice movements of the time, and Harris was both a product and a beneficiary.She spoke often about attending demonstrations in a stroller and growing up around adults "who spent full time marching and shouting about this thing called justice." In first grade, she was bused to school as part of the second class to integrate Berkeley public education.Harris’ parents divorced when she was young, and she was raised by her mother alongside her younger sister, Maya. She attended Howard University, a historically Black school in Washington, and joined the Alpha Kappa Alpha sorority, which became a source of sisterhood and political support over the years.After graduating, Harris returned to the San Francisco Bay Area for law school and chose a career as a prosecutor, a move that surprised her activist family.She said she believed that working for change inside the system was just as important as agitating from outside. By 2003, she was running for her first political office, taking on the longtime San Francisco district attorney.Few city residents knew her name, and Harris set up an ironing board as a table outside grocery stores to meet people. She won and quickly showed a willingness to chart her own path. Months into her tenure, Harris declined to seek the death penalty for the killer of a young police officer slain in the line of duty, fraying her relationship with city cops.Video above: Voters ask, what comes next?The episode did not stop her political ascent. In late 2007, while still serving as district attorney, she was knocking on doors in Iowa for then-candidate Barack Obama. After he became president, Obama endorsed her in her 2010 race for California attorney general.Once elected to statewide office, she pledged to uphold the death penalty despite her moral opposition to it. She refused to defend Proposition 8, a voter-backed initiative banning same-sex marriage. Harris also played a key role in a $25 billion settlement with the nation’s mortgage lenders following the foreclosure crisis.As killings of young Black men by police received more attention, Harris implemented some changes, including tracking racial data in police stops, but didn’t pursue more aggressive measures such as requiring independent prosecutors to investigate police shootings.Harris’ record as a prosecutor would dog her when she launched a presidential bid in 2019, as some progressives and younger voters demanded swifter change. However, during her time on the job, she also forged a fortuitous relationship with Beau Biden, Joe Biden’s son, who was then Delaware’s attorney general. Beau Biden died of brain cancer in 2015, and his friendship with Harris figured heavily years later as his father chose Harris to be his running mate. Harris married entertainment lawyer Douglas Emhoff in 2014, and she became stepmother to Emhoff’s two children, Ella and Cole, who referred to her as “Momala.”Harris had a rare opportunity to advance politically when Sen. Barbara Boxer, who had served more than two decades, announced she would not run again in 2016.In office, Harris quickly became part of the Democratic resistance to Trump and gained recognition for her pointed questioning of his nominees. In one memorable moment, she pressed now-Supreme Court Justice Brett Kavanaugh on whether he knew any laws that gave government the power to regulate a man’s body. He did not, and the line of questioning galvanized women and abortion rights activists.A little more than two years after becoming a senator, Harris announced her campaign for the 2020 Democratic presidential nomination. But her campaign was marred by infighting and she failed to gain traction, ultimately dropping out before the Iowa caucuses.Eight months later, Biden selected Harris as his running mate. As he introduced her to the nation, Biden reflected on what her nomination meant for “little Black and brown girls who so often feel overlooked and undervalued in their communities.”“Today, just maybe, they’re seeing themselves for the first time in a new way, as the stuff of presidents and vice presidents,” he said. What has Kamala Harris done in office as vice president?Once in the job, Harris worked to stem migration from Central America, but her efforts did not stop the movement of people leaving their corrupt and impoverished countries to seek safety and prosperity in the U.S.Nor was there much progress to be made on voting rights, another issue that was part of Harris’ portfolio. When Republicans limited ballot access in various states, Democrats lacked the necessary muscle in Congress to push back at the national level.Harris eventually carved out a role as the administration’s most outspoken advocate for reproductive rights after the U.S. Supreme Court overturned Roe v. Wade, the landmark case that had guaranteed abortion access nationwide.Video above: Presidential historian reacts to Biden's decisionMuch of Harris’ work has focused on bolstering her party’s coalition of women, young people and voters of color. And in halls of power dominated by men – both in Washington and around the world – she has remained keenly aware of her status as a political pioneer.She often repeated a line she credited to her mother: “Kamala, you may be the first to do many things, but make sure you’re not the last."Her full statement after Joe Biden endorsed her“On behalf of the American people, I thank Joe Biden for his extraordinary leadership as President of the United States and for his decades of service to our country. His remarkable legacy of accomplishment is unmatched in modern American history, surpassing the legacy of many Presidents who have served two terms in office.“It is a profound honor to serve as his Vice President, and I am deeply grateful to the President, Dr. Biden, and the entire Biden family. I first came to know President Biden through his son Beau. We were friends from our days working together as Attorneys General of our home states. As we worked together, Beau would tell me stories about his Dad. The kind of father—and the kind of man—he was. And the qualities Beau revered in his father are the same qualities, the same values, I have seen every single day in Joe’s leadership as President: His honesty and integrity. His big heart and commitment to his faith and his family. And his love of our country and the American people.“With this selfless and patriotic act, President Biden is doing what he has done throughout his life of service: putting the American people and our country above everything else.“I am honored to have the President’s endorsement and my intention is to earn and win this nomination. Over the past year, I have traveled across the country, talking with Americans about the clear choice in this momentous election. And that is what I will continue to do in the days and weeks ahead. I will do everything in my power to unite the Democratic Party—and unite our nation—to defeat Donald Trump and his extreme Project 2025 agenda."We have 107 days until Election Day. Together, we will fight. And together, we will win."