Speaker Nancy Pelosi's reign over the House Democratic Party is officially coming to a close, and she's passing the baton to a new generation of leaders.

Why it matters: Those who have served loyally by her side for nearly two decades — Majority Leader Steny Hoyer and Whip Jim Clyburn — have said they are ready to step aside to allow for the new guard to ascend to power. That's given way to the rise of Reps. Hakeem Jeffries (D-N.Y.), Katherine Clark (D-Mass.) and Pete Aguilar (D-Calif.).

• The three have developed a close relationship while serving together in leadership, and they'll run as a united front with buy-in from a large swath of the Democratic caucus that is eager to usher in a younger and more diverse group of leaders to power.

Driving the news: In an emotional and historic speech on the House floor Thursday afternoon, Pelosi announced she will not run again for leadership, though she plans to remain in the House as a lawmaker.

• She made way for the new guard in her remarks, declaring: “The hour has come for a new generation to lead the Democratic Caucus that I greatly respect.”

83-year-old Maryland Democrat Steny Hoyer has been coy for months about whether he'd try to replace Pelosi as leader should she step down. But he announced Thursday that he, like Pelosi, does not plan to seek another role in leadership.

• Meanwhile Clyburn, the 82-year-old South Carolinian, plans to run for the assistant Democratic leadership position, Punchbowl News first reported. Clyburn, who serves with Jeffries on the Congressional Black Caucus, has long been supportive of Jeffries' ascension.
• “Speaker Pelosi has left an indelible mark on Congress and the country, and I look forward to her continued service and doing whatever I can to assist our new generation of Democratic Leaders which I hope to be Hakeem Jeffries, Katherine Clark, and Pete Aguilar.”

Worth noting: There is a chance, though it is unlikely, that other members make their own bid to replace Pelosi. As of now, no one else has stepped forward to challenge Jeffries for the role.

Get to know the likely new leaders below.

Hakeem Jeffries

The 52-year-old New Yorker represents parts of Brooklyn and Queens, and is the fifth-ranking Democrat in Congress. Jeffries has long been considered the frontrunner to replace Pelosi and is widely favored to succeed her.

• Pelosi was the first woman to be elected speaker roughly two decades ago, and some Democrats have an eye toward naming a similarly historic replacement.
• Jeffries would be the first Black lawmaker in history — in either party — to be the leader of either chamber.

What to watch: Jeffries and Pelosi are close, but Jeffries hasn't built a strong relationship with the left-wing of his party. Rep. Alexandria Ocasio-Cortez (D-N.Y.) had previously considered trying to take Jeffries out by launching a primary challenge against him in the 2020 cycle.

• Jeffries and Rep. Kevin McCarthy (R-Cali.) have grow accustomed to trading barbs at each other, usually in the press, but will have to figure out a working relationship if they both end up leading their respective parties.

Katherine Clark

The 59-year-old has become a popular member within the caucus, helping freshmen members settle into their new jobs through her role as Assistant Speaker.

• Apart from Pelosi, she is the only other woman on the caucus' leadership team. Continuing to have a female presence at the top echelon's of power following Pelosi's departure is important to many members of the caucus, including Clark.
• "I think there is something about women’s leadership styles that are built on listening, building consensus and listening not just to people — our constituents — but also to my colleagues that come from different districts, have different concerns, different pressures than I do," Clark told Axios in an interview last year.
• Clark has three children, which has motivated her interest in child care issues and her affinity for the needs of fellow lawmakers balancing work, life and new jobs.

Pete Aguilar

The 43-year-old, currently Democratic Caucus Vice Chair, is the highest-ranking Hispanic in Congress.

• He has risen to prominence this year in part to his position on the high-profile January 6 Select Committee investigating former President Trump's involvement in the Capitol attack.
• Aguilar is seen as one of the most talented communicators in the House and has gained a reputation for being a team player that will look our for his fellow colleagues.
• Aguilar, former mayor of Redlands, California, also played a central role in a bipartisan immigration reform push in 2018 that won him credit across his party.

Editor's note: This story has been updated with additional details.