Former Vice President Joe Biden promised on Sunday to nominate the first Black woman to the U.S. Supreme Court should he win the White House in November. 

He made the vow during a Democratic presidential debate with U.S. Sen. Bernie Sanders (I-VT). Pitching to women voters, and Black women voters in particular, has become an important part of Biden’s campaign. He also committed during the debate to choose a woman as his running mate, which he’s hinted at doing in the past.

A lot needs to happen between now and November before a Black woman is nominated—let alone confirmed—to the Supreme Court. And Biden can make all the promises he wants. None of those promises will mean anything if Democrats fail to win the Senate in November, since we can no longer assume a Republican majority in the chamber will ever hold hearings for a Democratic president’s Court nominee.

But it’s good of Biden to make the pledge. Sanders should follow suit. And whoever ends up the Democratic nominee should make fixing the courts—starting with diversifying the bench—a tentpole of their presidential run. The future of any Democratic reform likely depends on it.

But who could Biden choose for an open Court seat? Here are six options.

Ketanji Brown Jackson

Judge Ketanji Brown Jackson of the United States District Court for the District of Columbia is an obvious choice. A former clerk of Supreme Court Justice Stephen Breyer, Jackson was nominated to the federal bench in 2012 by President Barack Obama and is related by marriage to former Republican Speaker of the House Paul Ryan.

Jackson is 49—young by federal judge standards—and Obama reportedly considered her to fill the Supreme Court vacancy created by the death of Justice Antonin Scalia in 2016. In November 2019, Judge Jackson ruled that former White House Counsel Don McGahn must comply with a subpoena issued by the House Judiciary Committee to testify before Congress during the impeachment inquiry into President Donald Trump. The U.S. Department of Justice appealed that ruling. The full U.S. Court of Appeals for the District of Columbia Circuit will hear that appeal later this year. 

Kamala Harris

Sen. Kamala Harris (D-CA) would be a formidable force on the bench. While attorney general for California, Harris refused to defend Proposition 8, the state’s ban on same-sex marriage that the Supreme Court ultimately declared unconstitutional in 2015 in the historic decision Obergefell v. Hodges. As a member of the Senate Judiciary Committee, Harris was one of the toughest and most vocal critics of Justice Brett Kavanaugh. A Harris appointment would not risk a Senate seat for Democrats—California Gov. Gavin Newson, a Democrat, would nominate her replacement. Harris endorsed Biden for president this month.

Bernice Donald

Judge Bernice Donald of the Sixth Circuit Court of Appeals would be the first former public defender on the Court. Judge Donald was first nominated to the district court by former President Bill Clinton and then the Sixth Circuit by Obama. 

In October, Judge Donald issued a scathing dissent in a decision upholding a Kentucky law mandating an ultrasound prior to an abortion. “The Commonwealth has coopted physicians’ examining tables, their probing instruments, and their voices in order to espouse a political message, without regard to the health of the patient or the judgment of the physician,” she wrote in her dissent. “Armed with the title ‘informed consent,’ the majority affirms this practice as constitutional.”

The Supreme Court declined to intervene in the Kentucky dispute, leaving that Sixth Circuit decision in place. 

Johnnie Rawlinson

In 2000, Judge Johnnie Rawlinson was the first Black woman appointed to the Ninth Circuit Court of Appeals. In 1980, Judge Rawlinson was one of two Black women first admitted to practice law in Nevada and was rumored to be on Obama’s shortlist of Supreme Court nominees. 

Ojetta Rogeriee Thompson

Ojetta Rogeriee Thompson is the first black woman and second woman to serve as a federal judge on the First Circuit Court of Appeals. Judge Thompson began her career as a cashier at the Providence, Rhode Island Civic Center before eventually working as an intern for Rhone Island Legal Services and then as a staff attorney doing public interest law. In 2009, Obama nominated Judge Thompson to the First Circuit; she was confirmed unanimously in 2010. 

Leondra Kruger

California Supreme Court Associate Justice Leondra Kruger could be a Supreme Court nominee for either Biden or Sanders. Justice Kruger, 43, is a former clerk to Supreme Court Justice John Paul Stephens, and she served in the Obama administration’s Department of Justice. Justice Kruger was appointed to the California Supreme Court by then-Gov. Jerry Brown (D) in 2014 and was retained by voters for a full 12-year term in 2018. She is the second Black woman to serve on the California Supreme Court.