More than four years ago, Kamala Harris dropped out of the 2020 presidential election with a pledge: "I am still very much in this fight."

Now after nearly four years as vice president of the United States, she is left to prove that she, indeed, is ready for the fight.

Harris, the former district attorney of San Francisco, attorney general of California, U.S. Senator representing the Golden State, is now the frontrunner for the 2024 Democratic presidential nomination after President Joe Biden announced he was leaving the race and offered his full-throated endorsement to his right-hand woman.

"My very first decision as the party nominee in 2020 was to pick Kamala Harris as my Vice President. And it’s been the best decision I’ve made. Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year," Biden said in a social media post shortly after he said he was stepping aside.

That post was followed up with a call to donate to her campaign: a link to an ActBlue donation page for the Biden-Harris campaign that, at its top, asks voters to "donate to elect Kamala Harris."

In a statement of her own, Harris said that she is "honored to have the President’s endorsement and my intention is to earn and win this nomination," adding she "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," she said Sunday. "Together, we will fight. And together, we will win."

If tapped to be the nominee, Harris, 59, will serve as a foil to Trump's age and could set the stage for the next generation of Democrats in 2028 and beyond.

Her first test of her poltical mettle came in San Francisco. She arrived to the political stage as California’s top cop, but largely avoided the state legislature as she focused on isues of maternal mortality and criminal justice. Her election to the U.S. Senate came the same day as Donald Trump won the White House, putting her in a position to oppose Trump at every turn.

Now, as she prepares to take over the campaign she built with Biden, her next great challenge might be unifying Democrats — and donors — as they look to once again defeat Trump at the ballot box.

So who is Kamala Harris, and where does she stand on key issues? Read more to find out.

Harris in the Golden State

Harris is the daughter of academic immigrant parents who met at the University of California, Berkeley, in the 1960s: Shyamala Gopalan, who emigrated to America from India, was a biomedical scientist who furthered cancer and oncology research, and Donald Harris, a retired economics professor who emigrated to the United States from Jamaica.

She was born in Oakland, California, a short distance away from Berkeley, where she would spend much of her childhood. After graduating from high school, Harris attended Howard University, the Washington, D.C.-based historically Black university, where she spent her self-professed "formative years" and first discovered her love of politics.

“The thing that Howard taught me is that you can do any collection of things, and not one thing to the exclusion of the other. You could be homecoming queen and valedictorian. There are no false choices at Howard," Harris said, according to her Howard alumni profile.

After graduating from Howard, she earned her law degree at UC Hastings — now the University of Californa, San Francisco — and was admittd to the California Bar in 1990. Soon after, she was hired as a deputy district attorney in Alameda County.

Early in her career, she connected with Willie Brown, the charasmatic former mayor of San Francisco and then-Speaker of the California Assembly, and the two began dating. Controversy ensued when Harris was appointed by Brown to state boards, leading to allegations of cronyism that dogged her even until the 2020 presidential election.

In 2004, she was elected as the district attorney of San Francisco, becoming the first person of color to hold the position. She was immediately faced with a test of her campaign promise to never seek the death penalty: four months after being sworn in, a San Francisco police officer was shot and killed in the line of duty.

While her colleagues and contemporaries — including then-Sen. Dianne Feinstein — endorsed the death penalty for the killer, Harris sought, and succesfully won, a prison sentence of life without parole. Though she was lambasted publicly for her stance, she was supported by then-Mayor Gavin Newsom, now the governor of the state.

As attorney general of California, a position she won in 2010, Harris became an advocate for privacy rights, becoming the vanguard for user privacy against Big Tech companies and striking a deal mandating that app stores prominetly display privacy policies. She promised to not defend the Prop. 8 gay marriage ban in court, later successfully arguing before the state supreme court that it was an unconstitutional law.

Ms. Harris goes to Washington

In 2016, Harris ran for U.S. Senate to replace the retiring Sen. Barbara Boxer, herself a longtime fixture in the Golden State. She won the endorsement of then-Gov. Jerry Brown and cruised to victories in both the primary and the general election.

Her Senate tenure placed her at the forefront of the resistance to then-President Trump’s policies, as she fiercely challenged his appointments, attacked his immigration family separation policy and voted to convict Trump on charges of abuse of power and obstruction of Congress during his first impeachment trial.

Harris' tough lines of questioning during committee hearings brought her nationwide attention. She first rose to prominence during the questioning of Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein over the firing of FBI Director James Comey in 2017, and as a member of the Senate Judiciary Committee after Al Franken's resignation, she grilled then-Homeland Security Secretary Kirstjen Nielsen over the Trump administration's family separation policy at the border. 

She also played key roles in the confirmation hearings of Supreme Court nominee Brett Kavanaugh and the questioning of Attorney General William Barr after the release of special counsel Robert Mueller's report about Russian interference in the 2016 election.

Harris makes history as VP

Though Harris warred with then-candidate Joe Biden on the campaign trail to the 2020 election, she became one of the first high-profile Democrats to drop out of the contest. In August 2020, she was selected to be his running mate, becoming the first Black person, first Indian American and third woman to be picked as the vice presidential nominee for a major party ticket.

As vice president, she’s repeatedly used her position as president of the Senate to break ties on crucial votes, and reportedly is part of "every core decision-making meeting" with Biden, according to National Security Adivsor Jake Sullivan. Much of her tenure in office has seen Harris on the road, speaking at college campuses across the country, rallying for Democratic candidates or in support of key administration positions, including voting rights and post-Roe reproductive policies.

She's been the voice of the administration at events promising aid and investments in marginalized communities and among people of color, as when she marked an award of billions of dollars for projects addressing climate change in Charlotte, N.C. in April. Harris has also been the tip of the spear for the White House on abortion rights, continually drumming arguments that reproductive rights are a matter of freedom and that Donald Trump is responsible for the patchwork state of abortion protections across the country.

"Now, because of Donald Trump, one in three women of reproductive age in our country live in a state that has a 'Trump Abortion Ban,'" she said at an Arizona rally in April. 

"Y'all know I'm a former prosecutor: just look at the facts. Congress tried to pass a national abortion ban in 2017. And then President Trump endorsed it and promised to sign it if it got on his desk," she added later. Trump has spent his time on the campaign trail stating that he's not in favor of a nationwide abortion ban, but that he believes abortion is a matter best left to the states. 

But his running mate Ohio Sen. J.D. Vance, she recently noted, has voted to block protections for in vitro fertility treatments and indicated support for a national ban on abortion. He's also decried the passage of state constitutional amendments enshrining abortion protections.

"What we have seen is when the American people are presented with this issue, regardless of what party they're registered to vote, they stand for freedom," Harris said in a Michigan rally on Wednesday.

Harris has also been the point person for the administration on seeking to address the root causes of migration -- a topic that the immigration-obsessed Trump campaign has already begun to hammer her on, shifting blame from Biden and onto her for increased illegal border crossings. She was tasked with negotiating with Mexico and several Central American countries on long-term fixes

A joint task force headed by the Department of Justice has led to more than 220 human trafficking convictions in U.S. courts, successful extraditions of foreign leadership targets and indictments, arrests and convictions in foreign allies, according to the White House. A 2024 report examining the Root Causes strategy published by the United States Agency for International Development noted that migration from northern Central American countires has fallen from highs in 2021 to 2023, and that the trend is lowered, challenges still exist. Central American economies, government corruption and injustice are pervasive, the report says. 

What challenges could Harris face as the Democratic nominee?

After Biden’s performance in his June debate against Trump, Harris was thrust into the spotlight as his heir apparent, the most-likely person to take over the campaign from a logical perspective — as Biden’s vice president — and a logistical perspective, as the only person who could take over the campaign’s vast war chest.

The question is, can she win over the Democrats — and their megadonors — who may have questions about her electability?

"If you think that there is consensus among the peopel who want Joe Biden to leave, that they will support Kamala, Vice President Harris, you would be mistaken," New York Rep. Alexandria Ocasio-Cortez said in a social media livestream earlier this week. "I’m in these rooms, I see what they say in conversations. A lot of them are not just interested in removing the president, they are interested in removing the whole ticket."

Should the ticket be removed entirely, and the Democrats opt for an open contest at the Democratic National Convention, a multi-day nomination process could lead to electoral chaos, Ocasio-Cortez said. Further, that could lead to any number of legal challenges across the states.

"Guess what: Republicans, they mount that legal challenge? The possibility of our election being decided by a Supreme Court ruling skyrocket," Ocasio-Cortez said.