Washington — The Senate on Thursday will vote to confirm Judge Ketanji Brown Jackson to the Supreme Court, with President Biden’s nominee on the cusp of making history as the first Black woman to serve on the nation’s highest court.

Jackson received a boost in her path to confirmation this week when Republican Sens. Mitt Romney of Utah and Lisa Murkowski of Alaska announced they would support her nomination, all but assuring she will win approval from the Senate. The two Republicans, along with Sen. Susan Collins of Maine, are expected to be the only GOP senators to join with all members of the Democratic caucus in voting in favor of Jackson’s nomination.

The Senate cleared a procedural hurdle early Thursday afternoon, voting 53-47 to proceed to a final vote, expected around 1:45 p.m. ET. Vice President Kamala Harris, the first woman and first woman of color to hold the role, will preside over the Senate during the vote, her office announced.

“It will be a joyous day: joyous for the Senate, joyous for the court, joyous for America,” Senate Majority Leader Chuck Schumer said on the Senate floor Thursday, noting that “America today is taking a giant step toward making our union more perfect.”

“People sometimes talk about standing on the shoulder of giants,” he continued. “Well, Judge Jackson will go down in history as an American giant upon whose shoulders others will stand tall, and our democracy will be better off for it.”

Jackson’s expected confirmation to the high court is likely to be a significant component of Mr. Biden’s legacy and is his first opportunity to make his imprint on the Supreme Court. She will not take the bench immediately after her likely approval, though, as Justice Stephen Breyer, whose seat she will fill, is poised to retire at the end of the court’s term this summer.

Approval of Jackson’s nomination by the evenly divided Senate will cap a confirmation process that was marked by Republican attempts to paint her as a soft-on-crime activist judge who would legislate from the bench.

Their criticisms, which were rooted in Jackson’s sentencing record in child pornography cases while she was a federal trial court judge, failed to derail efforts from the White House and Democratic Senate leaders to drum up bipartisan support for Jackson’s nomination, piercing the partisan polarization of recent Supreme Court confirmations. But the accusations did provide Republicans with fodder as they position themselves as the law-and-order party ahead of the November midterm elections.

Democrats were aiming to confirm Jackson before senators leave town Friday for a two-week recess, and Senate leaders moved swiftly to begin the confirmation process after Mr. Biden, a former chairman of the Senate Judiciary Committee, announced Jackson as his pick for the Supreme Court in late February. With the president’s selection of Jackson, she became the first Black woman to be nominated to the high court. 

During confirmation hearings that spanned four days in March, Jackson endured nearly 24 hours of questioning from the 22 members of the Senate Judiciary Committee, after which the panel deadlocked on approving her nomination along party lines Monday.

The tie 11-11 vote in the Judiciary Committee forced a procedural vote in the full Senate to advance Jackson’s nomination. While the upper chamber voted to move Jackson’s nomination out of the committee, with three Republicans joining Democrats in the vote, the effort underscored how bitterly partisan recent confirmation fights have become and the near-unified GOP opposition to her appointment.

Ahead of the vote, Murkowski said in a statement announcing her support for Jackson that her decision rested in part on her rejection “of the corrosive politicization of the review process for Supreme Court nominees, which, on both sides of the aisle, is growing worse and more detached from reality by the year.”

Jackson will join the Supreme Court after serving for nearly a year on the U.S. Court of Appeals for the District of Columbia Circuit, considered the nation’s second most powerful court. In her first term on the high court, Jackson will hear a pair of cases involving admissions policies at Harvard College and the University of North Carolina, as well as redistricting and religious liberty disputes. Jackson has pledged to recuse herself from the Harvard legal fight, as she is a member of the school’s Board of Overseers, one of its two governing bodies.

While her appointment will not alter the ideological composition of the Supreme Court, which boasts a 6-3 conservative majority, Jackson will be the second-youngest justice at 51 years old, likely ensuring decades of service. Her appointment also marks the first time two African Americans will sit on the Supreme Court simultaneously and the first time there will be four women on the high court serving together.

Jackson also brings professional diversity to the bench, having served as an assistant public defender and on the federal trial court in Washington. There has never been a Supreme Court justice to have worked as a public defender, and Justice Sonia Sotomayor is the only current member of the court to have served on a U.S. district court. She also was a member of the U.S. Sentencing Commission and worked in private practice after graduating from Harvard and Harvard Law School.

During her confirmation hearings, Jackson demonstrated the arc of the nation’s history through the story of her life and that of her parents — from her mother and father attending segregated schools in Florida to her being poised to become the first Black woman to sit on the nation’s highest court “in one generation.” Remarking on her legal career, she pledged to be an independent jurist who approaches cases from a position of neutrality.

“I decide cases from a neutral posture. I evaluate the facts and I interpret and apply the law to the facts of the case before me without fear or favor, consistent with my judicial oath,” she told senators at her confirmation hearings. “I know that my role as a judge is a limited one, that the Constitution empowers me only to decide cases and controversies that are properly presented, and I know that my judicial role is further constrained by careful adherence to precedent.” 

Those assurances, though, did little to persuade most Republican senators.

Many took issue with Jackson’s refusal to label her judicial philosophy, which she described as a multi-step methodology, and unwillingness to take a stance on adding seats to the Supreme Court, even as they acknowledged her legal qualifications. The most frequent criticisms of Jackson, though, centered on her sentencing of offenders in child pornography cases, which GOP senators claimed was below federal guidelines.

“Judge Jackson’s nomination started off on the wrong foot because President Biden promised he’d only nominate a judicial activist,” Senate Minority Leader Mitch McConnell said Wednesday. “I’d hope maybe the judge’s record and testimony would persuade us otherwise, maybe she would persuade the Senate she understands the proper judicial role. Unfortunately, what happened was just the opposite.”

GOP Sen. Lindsey Graham of South Carolina said in remarks Monday that had Republicans controlled the Senate, Jackson would not have received a confirmation hearing. He also forecasted that if the GOP wins back the majority in the upper chamber, judicial nominees put forth by Democrats would be rejected if they’re deemed too liberal.

“We’re supposed to be like trained seals over here, clapping when you appoint a liberal,” Graham said. “That’s not going to work.”

The South Carolina senator was one of three Republicans, with Collins and Murkowski, to support Jackson’s nomination to the D.C. Circuit, but he intends to vote against confirming her to the Supreme Court.

Democrats, meanwhile, sought throughout the confirmation process to highlight the historic nature of Jackson’s nomination and eventual approval by the Senate.

“Judge Jackson has given me every reason to be hopeful not only for our court, but for the country,” Sen. Patrick Leahy, a Democrat from Vermont, said Monday. “Judge Jackson just being nominated has already helped move our country forward.”