Associate Justice Stephen Breyer has officially announced his retirement from the United States Supreme Court, ending a 27 year-long tenure on the nation’s highest court.

Breyer’s retirement was first reported by NBC News on Wednesday that he would retire at the end of the current Supreme Court term, which likely ends in the summer. He formally announced it at a press conference on Thursday at the White House with President Joe Biden.

In his speech at the press conference, Breyer spoke of the United States as an “experiment,” referring to the Constitution and democracy, and encouraged young people to uphold these principles.

“And I’ll tell you something: you know who will see whether that experiment works? It’s you my friend,” he explained. “It’s you, mister high school student. It’s you, mister college student. It’s you, mister law school student. It’s us, but it’s you. It’s that next generation and the one after that. My grandchildren and their children. They’ll determine whether the experiment still works. And of course, I am an optimist, and I’m pretty sure it will.”

The retirement of Breyer, regarded as a member of the Court’s liberal wing, will give Biden an opportunity to appoint a justice to the Supreme Court. During his 2020 campaign, Biden pledged to nominate a black woman to the Court, a historic pledge that he reaffirmed at the press conference.

“The person I nominate will be of extraordinary qualifications, character, experience and integrity,” he stated. “And that person will be the first Black woman ever nominated to the United States Supreme Court. It’s long overdue in my opinion. I made that commitment during the campaign for president and I will keep that commitment.”

Biden said that he will announce his nominee by the end of February. Potential candidates include DC Circuit Court Judge Kentaji Brown Jackson and California Supreme Court Justice Leondra Kruger.

The confirmation process will be the first to occur in an evenly split 50-50 Senate. Democrats can confirm the nominee without any Republican support due to the 2017 removal of the 60-vote threshold to break a filibuster on the nominee.

A party-line vote would require all 48 Democrats and two independents to unite behind the nominee, including the support of critical moderates Joe Manchin (D-WV) and Kyrsten Sinema (D-AZ). Though Manchin and Sinema have broken with their Democratic colleagues on numerous issues, they both have voting records of 100% on Biden’s nominees for the lower courts according to FiveThirtyEight.

Manchin, the most conservative Senate Democrat, said on Thursday that he would be open to confirming someone more liberal than him, and emphasized the character of the nominee over ideology.

Senate Majority Leader Chuck Schumer (D-NY) vowed for a quick confirmation hearing, writing in a statement released Wednesday that Biden’s nominee “will receive a prompt hearing in the Senate Judiciary Committee and be considered and confirmed by the full United States Senate with all deliberate speed.”

If the nominee is confirmed, it will likely not change the Court’s ideological composition, which has a 6-3 conservative majority. However, this nominee would solidify the liberal wing of the Court and potentially serve for decades.

Breyer was nominated to the Court by President Bill Clinton in 1994, and was confirmed with an 87-9 vote. Prior to that, he taught at Harvard Law School and served as a judge of the U.S. Court of Appeals for the First District.

Following his retirement, Breyer’s Supreme Court colleagues issued statements about him. Chief Justice John Roberts called him “a tireless and powerful advocate for the rule of law in the United States and abroad,” while Brett Kavanaugh recognized him as “a scholar and a gentleman, an independent judge and fierce patriot.”