Democratic National Committee Chair Jamie Harrison and Minyon Moore, the DNC convention chair, just sent members a note, obtained by ABC News, saying guidance on the formal nomination process following President Joe Biden's exit from the race will arrive "in the coming days."

“While this situation is unprecedented, the DNC is ready to undertake a transparent and orderly process to move forward as a united Democratic Party and select a nominee," they said in their message. "This process will be governed by rules and procedures of our Party, and we know that all of you are ready to take your responsibility seriously to swiftly nominate a candidate who will defeat Donald Trump in November. In the coming days, you will hear more from us on the next steps to formally select our nominee. As we move forward, our values as Democrats will remain the same – protecting our basic freedoms, fighting for working families, and saving our democracy from the threat of dictatorship."

The pair said the DNC will "honor" Biden's "legacy with a firm commitment to nominating and electing a Democratic president this November" who will continue the strides he has made as president.

As of Friday, Democrats planned to continue their virtual nomination process to ensure that Biden and Harris were on the ballot in all 50 states. That was, of course, before Biden made his announcement on Sunday afternoon.

-ABC News' Brittany Shepherd

The United Auto Workers Union has reacted to the news that President Joe Biden has endorsed Vice President Kamala Harris for president.

While calling Harris an "ally," the UAW spokesperson stopped short of offering an endorsement, noting its board will meet soon.

In a statement to ABC News, a UAW spokesperson said, "Our UAW International Executive Board, elected by the membership of the UAW, will meet in the coming days to decide our next steps. Vice President Harris has been an ally and a champion for the UAW and the whole working class, and we're excited to defeat Donald Trump and the billionaire class at the ballot box this November."

The UAW had endorsed Biden for president earlier this year.

-ABC News' Briana K. Stewart

Barely two hours after announcing it had raised $27.5 million following President Joe Biden's exit from the presidential race and endorsement of Kamala Harris for president, ActBlue says it has now processed $46.7 million in donations.

"UPDATE: As of 9pm ET, grassroots supporters have raised $46.7 million through ActBlue following Vice President Kamala Harris’ campaign launch," the small-dollar donor fundraising platform said in a statement. "This has been the biggest fundraising day of the 2024 cycle. Small-dollar donors are fired up and ready to take on this election."

-ABC News' Gabriella Abdul-Hakim

Vice President Kamala Harris' husband, second gentleman Doug Emhoff, commented for the first time Sunday night since President Joe Biden announced his decision to drop out of the 2024 race.

"President Biden is a true patriot who leads our nation with honesty, decency, and integrity," Emhoff wrote in a post on X.

Praising Biden's work with Harris, Emhoff said, "They have fought tirelessly for families and communities, delivering for Americans across our nation."

"I am so proud of their accomplishments and thankful for their leadership," he added.