The US Senate has confirmed Judge Amy Coney Barrett to the Supreme Court in a victory for President Donald Trump a week before the presidential election.
Mr Trump’s fellow Republicans voted 52-48 to approve the judge, overcoming the unified opposition of Democrats.
Her appointment seals for the foreseeable future a 6-3 conservative majority on the top US judicial body.
Democratic presidential candidate Joe Biden called the move rushed and unprecedented.
Senate Democratic leader Chuck Schumer said that by going ahead with the vote so close to the election the Republican majority was “lighting its credibility on fire”.
Justice Barrett, 48, took the oath of office at the White House alongside President Trump.
Only one Republican, Senator Susan Collins, who faces a tough re-election battle in Maine, voted against the president’s nominee in Monday evening’s vote.
The new justice is the third appointed by the Republican president, after Neil Gorsuch in 2017 and Brett Kavanaugh in 2018.
The federal appeals court judge from Indiana fills the vacancy left by Justice Ruth Bader Ginsburg, a liberal icon who died last month.
President Trump, just returned from campaigning in Pennsylvania, presided over Justice Barrett’s swearing-in ceremony on Monday night.
Mr Trump said: “This is a momentous day for America, for the United States constitution and for the fair and impartial rule of law.”
He added: “She is one of our nation’s most brilliant legal scholars and she will make an outstanding justice on the highest court in our land.”
Supreme Court Justice Clarence Thomas, a conservative, administered the oath of office to his new colleague.
Justice Barrett said afterwards: “A judge declares independence not only from the Congress and the president, but also from the private beliefs that might otherwise move her.
“The judicial oath captures the essence of the judicial duty: the rule of law must always control.”
The ceremony took place on the south lawn of the executive mansion, a month after a similar event to unveil Justice Barrett as the president’s nominee was linked to a Covid-19 outbreak that was followed by the president himself testing positive for the disease.