Explained | What's next for the Harris campaign

President Joe Biden endorsed Vice President Kamala Harris to lead the presidential ticket after ending his reelection campaign Sunday, raising the chance that she could be the first Black woman to be president of the United States.

Harris, in many ways, has been preparing for this moment for the past year as she emerged as one of the Biden campaign's more aggressive voices on abortion rights and attacks on former President Donald Trump. Biden spoke to Harris on Sunday morning before he posted a letter online informing the world that he would be stepping down as the Democratic nominee.

In another post less than a half-hour later, he endorsed Harris, who quickly issued a statement saying she intended to "earn and win this nomination."

There are many questions that Harris and her team will face in the days ahead.

What about her campaign?

Harris will now need to take over the vast infrastructure of Biden's campaign, which has roughly 1,300 staff members and dozens of offices around the nation. There are signs that is already happening.

On a call with the Biden campaign staff Sunday, Jen O'Malley Dillon, the Biden campaign chair, and Julie Chavez Rodriguez, the Biden campaign manager, informed the staff members that they were all now working for Harris for President, according to two people who listened to the call. "We're all going to do it the same," Chavez Rodriguez said.

Harris already has connections to Chavez Rodriguez, who served as Harris' state director when she was in the Senate. Chavez Rodriguez later worked on her unsuccessful 2020 campaign for president.

The vice president has ramped up her own campaign team in the past year -- although they maintained it was just to support her as Biden's No. 2. Her advisers for her vice presidential campaign team include Brian Fallon, the communications director, who also worked for Hillary Clinton's 2016 campaign, and Sheila Nix, the chief of staff, who held the same position in Jill Biden's office when Biden was vice president.

If Harris is the nominee, who will be her vice presidential pick?

Well aware of the cold reality of identity politics, Democrats assume that if Harris, the first Black and Asian American woman to be vice president, were nominated to the presidency, she would most likely balance her ticket with a white man.

An emerging favorite is North Carolina Gov. Roy Cooper, a Southern moderate who works with a Republican legislature and has joined Harris in attacking Republicans over abortion rights restrictions. Harris got to know Cooper when they were both attorneys general of their states. The vice president traveled to North Carolina on Thursday to hold a campaign rally with Cooper.

Another candidate mentioned is Kentucky Gov. Andy Beshear, who won a second term in a conservative state last year. Pennsylvania Gov. Josh Shapiro could theoretically help Democrats capture a swing state battleground critical to victory in November. Illinois Gov. J.B. Pritzker, a billionaire who could provide substantial financing for the campaign, is another possibility.

California Gov. Gavin Newsom, an energetic foil to Trump, has also been mentioned, but a West Coast liberal would not be the most obvious candidate to help Harris in the vital swing states of Pennsylvania, Michigan and Wisconsin. If Harris wants to make history and roll the dice, she could select Michigan Gov. Gretchen Whitmer, which would test whether America is ready for two women in the White House.

Whom does she rely on?

After a series of stilted appearances when the new vice president showed little command of policy, Harris shook up her team of senior aides and in 2022 brought veteran political operatives into her inner circle.

Harris elevated Lorraine Voles, who served as director of communications for Vice President Al Gore, to be her chief of staff. Voles, a crisis communications expert, had previously advised Harris on communications and had worked on the presidential campaigns of Michael Dukakis in 1988 and Walter Mondale in 1984.

Harris has also promoted Kirsten Allen, who worked on Harris's short-lived 2020 presidential campaign, from press secretary to communications director. Stephanie Young joined Harris' staff last year as a senior adviser focused on outreach and messaging from her role working with a voting rights organization founded by Michelle Obama.

Harris has also worked closely with Jeffrey D. Zients, the White House chief of staff.

Harris has relied on Democratic operatives, donors and lawmakers she has worked with in her previous roles for advice. They have counseled her to lean into her own voice and appeal to reach crucial voting blocs, including business leaders and Black men.

What about the money and delegates?

Biden made clear Sunday that Harris would take control of at least part of his campaign apparatus when he posted a link to what was his "Biden-Harris" donation page. Now, it states in bold letters: "Donate to Elect Kamala Harris."

Harris will most likely have no interruption in taking control of the $96 million the Biden-Harris campaign held as of June 30. The money is held in the campaign accounts, and therefore, Harris would be able to use it to face Trump in November. This has been the thrust of her support from donors, who have rallied behind her in recent weeks.

Biden also gave Harris an advantage by endorsing her. But he cannot force the Democratic convention delegates to follow his lead. They are essentially free agents, able to vote for any candidate of their choosing.

Biden's endorsement will provide some influence on the delegates, but she does not automatically receive their votes.

Will the Democrats support her?

Harris drew endorsements from a range of influential Democrats on Sunday, including former President Bill Clinton, Hillary Clinton and the Congressional Black Caucus.

But there are still other prominent Democrats, such as Rep. Nancy Pelosi, D-Calif., the former House speaker, who said before Sunday that they would favor an open-primary contest, in which Harris would compete with other potential nominees. It is unclear whether Pelosi will continue to favor such a contest, and whether any potential candidates will be willing to challenge Harris and create more uncertainty in the party.

Notably, in a statement issued Sunday after Biden's decision to drop out, former President Barack Obama did not endorse Harris. "We will be navigating uncharted waters in the days ahead," Obama said. "But I have extraordinary confidence that the leaders of our party will be able to create a process from which an outstanding nominee emerges."

A person familiar with Obama's thinking said later Sunday that the former president was following the same policy of neutrality he adopted during the 2020 Democratic primaries, when Biden faced a field of competitors, and wanted to help unite the party once there was an official nominee.

But Rep. Robert Garcia, D-Calif., said in an interview that there would not be an open convention and that the Democratic Party would unite around Harris. He was co-chair for Harris' 2020 campaign, and she swore him in as mayor of Long Beach, California.

"It's not happening," Garcia said. "There will be no open convention. A lot of folks are going to take their cues from the president."

Harris also received the endorsement of Rep. James Clyburn, an influential South Carolina Democrat who helped revive Biden's campaign in 2020.

"I echo the good judgment he demonstrated in selecting Vice President Harris to lead this nation alongside him," Clyburn said in a statement, "and I am proud to follow his lead in support of her candidacy to succeed him as the Democratic Party's 2024 nominee for president."

Harris wasted no time in building support for her candidacy Sunday. She called Rep. Steven Horsford, D-Nev., chair of the Congressional Black Caucus, and said she would "run and earn it and win it," according to a congressional official familiar with the discussion.

Jaime Harrison, chair of the Democratic National Committee, issued a statement saying the next steps on the nomination process would be coming "in short order."

"The work that we must do now, while unprecedented, is clear," Harrison said. "In the coming days, the party will undertake a transparent and orderly process to move forward as a united Democratic Party with a candidate who can defeat Donald Trump in November."