President Joe Biden has formed a bipartisan commission to study potential US Supreme Court changes including expanding the number of justices beyond the current nine, a goal of some liberal Democrats hoping to end its conservative majority.
Under an executive order signed by the Democratic president, the 36-member commission will consider the "merits and legality" of potential reforms to the nation's top judicial body including adding justices or imposing term limits on their service instead of the current lifetime appointments.
The number of Supreme Court justices has remained at nine since 1869, but Congress has the power to change the number and did so several times before that. Imposing term limits would likely require a constitutional amendment.
White House Press Secretary Jen Psaki said the commission would represent the full political spectrum. It will include legal scholars, former federal judges and lawyers who have appeared before the court.
Biden promised during the presidential election campaign to establish the commission, which enabled him to avoid taking a firm position on the proposal floated by some liberals to expand the court, though he has opposed the idea in the past.
Republicans fiercely oppose what is sometimes called "court packing". Some Democrats and liberal activists have said all options including expansion must be considered to counter an entrenched conservative majority that could threaten abortion rights, civil rights, gun control and access to healthcare in the coming years.
Republican former president Donald Trump was able to appoint three justices, giving the court a 6-3 conservative majority.
Democrats accused Republicans of "stealing" a Supreme Court seat in 2016 when the Senate, then controlled by Republicans, refused to consider Democratic president Barack Obama's nomination of Merrick Garland to fill a vacancy left by the death of conservative Justice Antonin Scalia.
Senate Republicans, led by then-majority leader Mitch McConnell, said it would be inappropriate to confirm a justice during a presidential election year. Their gambit paved the way for Trump in 2017 to replace Scalia with another conservative, Justice Neil Gorsuch.
Democrats accused Republicans of hypocrisy last year when the Senate quickly confirmed Trump's appointment of conservative Justice Amy Coney Barrett a week before the presidential election after the death of liberal Justice Ruth Bader Ginsburg the previous month.
Calling it a "faux-academic study of a non-existent problem", McConnell blasted Biden's commission as a political attack on the court.