Explainer: Biden will step aside in the 2024 race. What happens next?

WASHINGTON, July 21 (Reuters) - President Joe Biden said on Sunday he would withdraw from the 2024 presidential election race, putting the United States into uncharted territory.

Biden endorsed Vice President Kamala Harris to be the Democratic nominee.

Before Biden's decision was made, Reuters spoke to Elaine Kamarck, a senior fellow at the Brookings Institution think-tank, a Democratic National Committee member and author of the book "Primary Politics" about the presidential nominating process, who explained how the process could work. Reuters also spoke to legal experts and Democratic Party officials.

Who will replace Joe Biden? Top Democrats tipped to win 2024 election nomination

President Joe Biden dropped out of the 2024 race for the White House on Sunday, ending his bid for reelection following a disastrous debate with Donald Trump that raised doubts about his fitness for office just four months before the election.

The decision comes after escalating pressure from Biden's Democratic allies to step aside following the June 27 debate, in which the 81-year-old president trailed off, often gave nonsensical answers and failed to call out the former president's many falsehoods.

President Biden: "I am endorsing Kamala Harris to be our next President of the United States"

"It has been the greatest honor of my life to serve as your President. And while it has been my intention to seek reelection, I believe it is in the best interest of my party and the country for me to stand down and to focus solely on fulfilling my duties as President for the remainder of my term.

For my part: my very first decision as the party nominee in 2020 was to pick Kamala Harris as my Vice President. And it’s been the best decision I’ve made.

Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year. Democrats — it’s time to come together and beat Trump."