Joe Biden and Kamala Harris Take on the US Presidential Election as a Team

"@JoeBiden can unify the American people because he's spent his life fighting for us. And as president, he'll build an America that lives up to our ideals," she tweeted.

For Harris, being elevated onto a presidential ticket is the political moment of a lifetime. And if they win, the telegenic but tough Californian would almost certainly become the frontrunner in the race for the 2024 or 2028 Democratic nomination.

Biden would be the oldest person to take the office, and there is broad speculation that should Biden win, he would serve one four-year term and groom his deputy to succeed him.

That puts Kamala Harris in the extraordinary position as the potential flag bearer of the Democratic Party.

Joe Biden is likely confident that Harris has the policy chops and governing experience to help lead on day one, and immediately step into the job as president if needed.

President Donald Trump poured scorn on Biden's announcement, saying he was "surprised" at his choice given what Trump called Harris's lackluster performance in the Democratic nomination race.

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"She did very poorly in the primaries," Trump told reporters at the White House. "And that's like a poll."

He went on to attack Harris for her role in the bruising confirmation hearings of Supreme Court Justice Brett Kavanaugh, calling her "the meanest, the most horrible, the most disrespectful of anybody in the US Senate."

But Harris, who beat out nearly a dozen other women to become the running mate, has shown she can parry such blows, a cherished quality for anyone facing an onslaught of negativity from a caustic president.

Biden's pick of Harris drew ringing endorsements from other quarters — including from Barack Obama, America's first black commander in chief.

"She is more than prepared for the job," tweeted Trump's predecessor. "This is a good day for our country. Now let's go win this thing."

Trailblazer

Harris has been a barrier-breaker for much of her career.

Her parents were immigrants to the United States — her father from Jamaica, her mother from India.