Vice President-elect Kamala Harris will step down from her California Senate seat Monday before taking up a more high-profile position in the chamber two days later, transition officials have announced.

When Harris makes history as the first woman, first Black person and first Indian American to serve as vice president, she'll also become president of the Senate. It's a largely ceremonial position — most of the time. But in a Senate that will be split 50-50, the tiebreaking vote she can cast will give Democrats control of the chamber. Given the hyperpartisanship in Congress, she may need to cast many tiebreaking votes.

California Gov. Gavin Newsom has tapped California Secretary of State Alex Padilla to fill the vacancy created by Harris' resignation. Padilla will be the state's first Latino senator and its first male senator in three decades. Harris' departure means there will be no Black woman in the Senate, and because of that, Newsom drew some criticism for appointing Padilla.

Harris leaves her Senate seat after just four years, less than a full term. Still, in the early weeks of her term in 2017, she quickly established a reputation as one of the Democrats' top committee questioners when President Trump's first Cabinet nominees came forward for confirmation.

Drawing on skills honed as a prosecutor in California, Harris peppered John Kelly on immigration issues and other matters during his confirmation hearing to head the Department of Homeland Security.

This set a tone that would last through Harris' term, and it was largely how she established a platform from which to launch her run for president in 2019.

Harris grilled former Attorney General Jeff Sessions, then later Bill Barr, during high-profile hearings, and she pressed Supreme Court Justice Brett Kavanaugh during his 2018 confirmation hearing in front of the Senate Judiciary Committee, which became a cultural flashpoint when sexual assault allegations against Kavanaugh surfaced mid-confirmation.

Harris also served on the Senate Intelligence Committee while the panel held hearings and investigations looking into Russia's interference in the 2016 election.

Harris was the 10th Black person to serve in the U.S. Senate and only the second Black woman.

At Wednesday's inauguration, Harris will be sworn in by Justice Sonia Sotomayor, the first woman of color to serve on the Supreme Court, who also administered the vice presidential oath to Joe Biden, now the president-elect, in 2013.

Harris will use two Bibles in the ceremony, according to a transition official, including one belonging to Regina Shelton, a family friend whom Harris viewed as a surrogate mother. Harris took the oath of office as both California attorney general and U.S. senator on Shelton's Bible.

Harris will also use a Bible previously owned by the late Justice Thurgood Marshall, the first Black member of the Supreme Court and Harris' lifelong political role model.

In a recent interview with NPR, Harris reflected on the moment that she'll take the oath of office as vice president. "I will be thinking about my mother, who's looking down from heaven. I will be thinking of all the people who are counting on us to lead," she said.

It's not yet clear what Harris' main focus will be as vice president. When Biden announced her as his running mate, he said he made Harris the same promise that Barack Obama gave him in 2008: that the vice president would be the "last person in the room" and a key adviser on every important administration decision.

That's something Harris has echoed when asked what policies she might take the lead on in the White House. "On every decision that we have made as an incoming administration, we're in the room together, Joe and I," Harris told NPR on Thursday. "I can't tell you how many meetings we've been in together that range from [vaccine distribution] to many other topics that are priorities for us."

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