On January 27, 2022, Justice Breyer announced that he would be retiring from the Supreme Court in the summer, after the justices ended their current term. After Breyer’s announcement, Biden reiterated his intention—first voiced as a campaign pledge—to nominate a Black woman to the Court. Jackson was one of several Black women who were regularly identified by the media as possible nominees.

Biden’s commitment to appoint a Black woman attracted criticism from conservatives and Republicans, who argued that Biden’s attempt to address historical racial and gender imbalances on the Court was equivalent to the discrimination that brought them about. Scholarly research suggests that the identity attributes of judges—including their race and gender—do predict differences in judicial decision making, but the effects are smaller than those associated with partisanship or ideology. To some, such differences in judicial outcomes suggest the importance of ensuring that judges as a whole accurately represent the population they serve. To others, the differences suggest problematic biases based on identity (though it is hardly clear which identity group’s perspective should count as the purportedly unbiased baseline). In February 2022 Biden announced his nomination of Ketanji Brown Jackson to replace Breyer, praising her “uniquely accomplished and wide-ranging background.” In her remarks thanking Biden for nominating her, Jackson called attention to one of her role models: Constance Baker Motley, the first Black woman to be appointed a federal judge.

As is typical of Supreme Court nominees, Jackson’s confirmation was formally supported by numerous entities and individuals, including advocacy groups for minority rights and women, along with current and former attorneys general, former federal prosecutors, former law enforcement officials, former law clerks, and law professors. Former federal judges Thomas B. Griffith and J. Michael Luttig—both conservatives who had been appointed to the bench by Republican presidents—strongly supported her confirmation. The American Bar Association’s Standing Committee on the Judiciary unanimously rated her as “well qualified” for the Supreme Court, the highest-possible category.

With the rise in partisan polarization in U.S. politics, judicial confirmation hearings have become contentious. Whereas past Supreme Court nominees had received substantial support (and numerous votes) from senators from the president’s opposing party, in the 21st century confirmation votes have increasingly split along party lines, and the confirmation hearings themselves have become more confrontational. During her hearings Jackson faced intense questioning from Republican senators who made misleading suggestions about her record as a judge, suggesting that she had imposed light sentences on criminals convicted of child pornography. In fact, Jackson’s record was consistent with that of other federal judges, including those nominated by Republican presidents. Similarly, Republican senators implied that Jackson’s work as a public defender indicated her own personal sympathy for the views and actions of criminals, a baseless contention that obscured the constitutional right of everyone charged with a crime to receive competent legal counsel.

Despite the harsh questioning of Republicans on the Senate Judiciary Committee, Jackson enjoyed high levels of public support, as reported in polls. Significant majorities or pluralities of survey respondents indicated their approval of her nomination and eventual confirmation. Democrats and even some Republicans in Congress praised her calm and patient demeanor while answering questions despite frequent—and often hostile—interruptions by Republican members of the Judiciary Committee.

The political and policy implications of Jackson’s confirmation were not as significant as those of some previous nominees. The confirmation of Justice Neil Gorsuch, who was 49 years old at the time of his nomination in 2017, ensured the preservation of a conservative majority on the Court; Justice Brett Kavanaugh’s confirmation in 2018 moved the Court’s median (ideological center) in a more conservative direction; and Justice Amy Coney Barrett’s replacement of liberal Justice Ruth Bader Ginsburg in 2020 established a six-to-three conservative supermajority (and moved the Court’s median farther to the political right)—all important changes to the political and strategic context of the Supreme Court that increased the likelihood of more-conservative rulings. In contrast, Jackson—who was expected to be a reliably liberal vote on the Court—was simply replacing a departing liberal justice in Breyer. The conservative supermajority was left intact, and the expected ideological balance of the Court was not altered by Jackson’s appointment.

The fact that the Senate was split 50–50 between Democrats and Republicans meant that Vice Pres. Kamala Harris, in her capacity as president of the Senate, would have the power to cast a tie-breaking vote, if needed. Republicans therefore had little chance of blocking Jackson’s confirmation. But Republican Sen. Lindsey Graham of South Carolina suggested that in the future—if his party regained control of the Senate while Biden was still president—Republicans would not allow a liberal nominee like Jackson to be confirmed.

Ultimately, Jackson won confirmation by a 53–47 Senate vote on April 7, 2022. Every Democratic senator, along with three Republican senators, voted in her favor. Soon after Breyer’s retirement became effective on June 30, 2022, Jackson was sworn in as his replacement.

Supreme Court opinions

Jackson’s first Supreme Court opinion concerned the Court’s refusal to hear an appeal of a lower court’s decision affirming a plaintiff’s conviction on charges of first degree murder. Her dissent, which was joined by Justice Sonia Sotomayor, argued that the Court of Appeals for the Sixth Circuit had applied the wrong standard for evaluating the trial court’s decision. The prosecution in the case had concealed evidence showing that its key witness “had an intellectual disability that may have affected [his] ability to remember, perceive fact from fiction, and testify accurately.” Jackson contended that the Sixth Circuit, in keeping with many Supreme Court precedents, should have based its decision on the ground that there was “reasonable probability” that the outcome of the trial would have been different had the jury been aware of the witness’s disability. Instead, the Sixth Circuit held that “reasonable probability” is equivalent to a higher standard, “more probable than not,” under which overturning the trial court’s ruling would not be necessary. According to Jackson, “that reasoning violated the spirit, if not the letter, of our many cases holding that the two standards are not the same and that ‘reasonable probability’ is a lower standard.” Jackson thus disagreed with the Court’s denial of the plaintiff’s appeal. “Given the substantial likelihood that the suppressed records would have changed the outcome at trial,” she wrote, “I would summarily reverse to ensure that the Sixth Circuit conducts its…analysis under the proper standard.”

In her first majority opinion for the Court, a unanimous ruling in Delaware v. Pennsylvania, et al. (2022), Jackson held that Delaware had wrongly taken control of some $250 million in abandoned financial products, similar to unused money orders, which had been purchased in several states from a company incorporated in Delaware. The products, according to Jackson, were “sufficiently similar” to money orders and therefore subject to a federal law that would have required their shared distribution among all the states in which they were purchased.

In Trump v. Anderson (2024), the Court overturned the Colorado Supreme Court’s decision to remove Donald Trump from the state’s Republican primary ballot because of his role in the January 6 U.S. Capitol attack. The state court held that Trump was disqualified from holding the office of president under Section 3 of the Fourteenth Amendment, which denies civil or military office to any individual who, having taken an oath to defend the U.S. Constitution, engages in an insurrection or rebellion against the United States or any state. Jackson and her fellow liberal justices, Elena Kagan and Sonia Sotomayor, concurred in the Court’s judgment that the state court could not remove Trump from the ballot, but they also forcefully criticized the Court’s majority for deciding other “novel constitutional questions” not directly relevant to the issue at hand, including its finding that Section 3 can be enforced only by the U.S. Congress.

In Trump v. CASA, Inc., et al. (2025), a case heard by the Court in response to an emergency request from the Trump administration, Jackson filed a bitterly critical dissent against the Court’s decision to stay three universal (nationwide) preliminary injunctions prohibiting enforcement of Trump’s executive order effectively ending birthright citizenship in the United States. In the estimation of the federal judges issuing the injunctions, Trump’s order clearly violated the citizenship clause of the Fourteenth Amendment of 1868 (“All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside”). While not addressing the question of whether Trump’s order was unconstitutional, the Court’s conservative majority found that federal courts lack the authority to issue injunctions that are “broader than necessary to provide complete relief to each plaintiff with standing to sue.” Thus, only the plaintiffs in each of the cases could be granted relief from enforcement of the executive order. In her dissent, Jackson argued that the Court’s decision was a grave threat to the rule of law in the United States:

I have no doubt that, if judges must allow the Executive to act unlawfully in some circumstances, as the Court concludes today, executive lawlessness will flourish, and from there, it is not difficult to predict how this all ends. Eventually, executive power will become completely uncontainable, and our beloved constitutional Republic will be no more.

Memoir

In 2024 Jackson published a memoir, Lovely One, recounting her childhood and family life—particularly the loving support of her parents—her academic determination and success from elementary school through Harvard University, and her legal career culminating in her appointment as a Supreme Court justice. The book discusses her early family history (her ancestors were enslaved plantation workers), the racism and segregation endured by her grandparents during the Jim Crow era, and her own more subtle experience of racist attitudes as a child and young adult. Lovely One also tells the story of her relationship with her husband and their two daughters, one of whom was diagnosed with autism spectrum disorder. The book’s title is the English translation of “Ketanji Onyika,” a West African phrase suggested as a name for Jackson by her aunt, who was then a Peace Corps volunteer in Africa.