Kamala Harris will make history if she becomes the next vice president of the United States in the election on Tuesday, and she will immediately be in a strong position to run for the top job four years from now.

If Joe Biden and his running mate Harris win the election, she would be the first woman, the first Black American, and the first Asian American to hold the country’s second-highest office.

Given his age, the 77-year-old Biden is not expected to seek a second term so Harris, 56, would be an obvious candidate for the Democratic nomination in 2024.

A US senator from California, Harris has a track record of shattering glass ceilings. She served as San Francisco’s first female district attorney and was California’s first woman of colour to be elected attorney general.

Her background in criminal justice could help a Biden administration tackle the issues of racial equality and policing after the country was swept by protests this year.

Harris, whose mother and father emigrated from India and Jamaica, respectively, had her sights set on becoming the first woman US president when she competed against Biden and others for their party’s 2020 nomination.

She dropped out of the race last December after a campaign hurt by her wavering views on healthcare and indecision about embracing her past as a prosecutor.

Biden looked beyond some of the harsh words Harris had for him in that campaign to name her his running mate in August. She has proven to be a valuable and polished stand-in, appealing especially to women, progressives and voters of colour who are critical to the party’s election hopes.

Harris, who developed a deep fundraising network during her Senate and White House bids, has been instrumental to Biden’s raking in record sums of money in the closing months of the campaign. Her selection sparked a burst of excitement in the Democratic base and among the party’s donors.

“Harris always made the most sense as a running mate for Biden because she had the ability to help him unify the Democratic coalition across racial and generational lines and was able to spike base enthusiasm,” said Joel Payne, a Democratic strategist who worked for Hillary Clinton’s 2016 presidential campaign.

A team player

Accusations from progressives that Harris did not do enough to investigate police shootings and wrongful conviction cases when she was California’s attorney general helped doom her own presidential run but have surfaced little during her time as Biden’s running mate.

President Donald Trump and his Republican re-election campaign have sought to paint Harris instead as a tool of the Democratic left who would wield power and influence behind the scenes in a Biden presidency.

She has seemingly put to rest concerns among some in the Biden camp prior to her selection that she would be too personally ambitious to make a trustworthy partner.

Harris has shown herself to be a team player, taking on a lower-profile role and holding virtual and in-person political events that sometimes drew little news coverage, while often speaking in terms of what Biden would do for the country if elected and making an impassioned case against Trump.

“Joe and I were raised in a very similar way,” Harris said of Biden at her October debate against Vice President Mike Pence. “We were raised with values that are about hard work, about the value and the dignity of public service and about the importance of fighting for the dignity of all people.”

Double duty

Harris has juggled her running mate duties with her day job in the Senate. Befitting her background as a prosecutor, she was a deft cross-examiner of US Supreme Court Justice Amy Coney Barrett at Barrett’s Senate confirmation hearing in October, weaving Biden’s campaign message on healthcare and climate change into her line of questioning.

As the Senate’s only Black woman, Harris emerged this year as a leading voice on racial justice and police reform after Minneapolis police killed African-American man George Floyd in May. She marched with protesters on the streets of Washington and won over some liberal skeptics.

Should Biden assume the presidency, Harris is expected to be a top adviser on criminal justice and judicial nominations, among other matters.

Asked on “60 Minutes” last month why, given Biden’s age, he believed Harris would be ready to step into the presidency if something happened to him, the presidential candidate rapidly fired off five reasons.

“Number one, her values. Number two, she is smart as a devil, and number three, she has a backbone like a ramrod. Number four, she is really principled. And number five, she has had significant experience in the largest state in the Union in running the justice department that’s only second in size to the United States Justice Department. And obviously, I hope that never becomes a question,” he said.

Harris is married to attorney Douglas Emhoff, who has been a fixture on the campaign trail. His two children from a previous marriage refer to their stepmother as “Momala”.