Joe Biden has selected California Sen. Kamala Harris as his running mate for the 2020 presidential election. 

The move makes Harris the first Black woman and first Asian American to appear on a major U.S. party's presidential ticket. Biden announced his decision Tuesday via Twitter and an email to his supporters.

"You make a lot of important decisions as president. But the first one is who you select to be your Vice President," Biden wrote. "I've decided that Kamala Harris is the best person to help me take this fight to Donald Trump and Mike Pence and then to lead this nation starting in January 2021 ... These aren't normal times. I need someone working alongside me who is smart, tough, and ready to lead. Kamala is that person."

While campaigning in the 2020 Democratic presidential primary, Harris took aim at Biden's record on racial issues—specifically calling out his work with pro-segregationist lawmakers in the 1970s. 

"I do not believe you are a racist and I agree with you when you commit yourself to the importance of finding common ground, but it's personal and it was hurtful to hear you talk about the reputations of two United States senators who built their reputations and career on the segregation of race in this country,"  Harris said to Biden during a June 2019 primary debate. "And it was not only that — you also worked with them to oppose busing."

Biden, who classified Harris' claims as a "mischaracterization of my position," took some questions from reporters in late July while holding some notes featuring Harris' name at the top. Underneath her name were bullet points that included phrases like "Do not hold grudges," "Great help to campaign," and "Great respect for her."

Harris formerly endorsed Biden for president back in March.

"[Biden] can unify the American people because he's spent his life fighting for us," she tweeted Tuesday, following Biden's announcement. "And as president, he'll build an America that lives up to our ideals. I'm honored to join him as our party's nominee for Vice President, and do what it takes to make him our Commander-in-Chief."

About a week after Harris endorsed Biden, the former vice president confirmed he would pick a woman as his vice president running mate. Speculation immediately began swirling around names like former national security adviser Susan Rice, Massachusetts Sen. Elizabeth Warren, Wisconsin Sen. Tammy Baldwin, California Rep. Karen Bass, Illinois Sen. Tammy Duckworth, and  former Georgia state representative Stacey Abrams. The latter was among the political figures who expressed support for the Biden's VP selection.

You can read other reactions to the Biden-Harris ticket below.

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