Some progressives are urging liberal US Supreme Court justice Stephen Breyer to retire to ensure they can install a like-minded successor.

Mr Breyer was appointed to the court more than 26 years ago by President Bill Clinton and now some progressives are hoping to avoid a repeat of the scenario which saw then president Donald Trump successfully nominate a conservative successor to the liberal Ruth Bader Ginsburg last year.

Ms Ginsburg, who died aged 87, had similarly been urged to step aside while Democrats controlled the nomination process during Barack Obama’s presidency but she refused to do so.

Mr Trump replaced the liberal Ms Ginsburg with a young conservative, Justice Amy Coney Barrett, and cemented a 6-3 conservative majority on the court just over a month before he lost his bid for a second term.

Now Mr Breyer, who is 82, finds himself in a similar situation as the oldest member of the court.

With spring comes the start of the period in which many justices have announced their retirement.

Some progressives say it is time for Mr Breyer to go, without delay.

Other liberal voices have said Mr Breyer should retire when the court finishes its work for the term, usually by early summer.

“He should announce his retirement immediately, effective upon the confirmation of his successor,” University of Colorado law professor Paul Campos wrote in The New York Times on Monday.

Mr Campos’ plea stems from the Democrats’ tenuous hold on power.

A Democrat, President Joe Biden, lives in the White House and his party runs the evenly divided Senate only because the tie-breaking 51st vote belongs to Vice President Kamala Harris.

But there is no margin for a senator’s death or incapacitating illness that could instantly flip control to Republicans.

Mr Campos noted that the party composition of the Senate has changed more often than not in each two-year session of Congress since the end of the Second World War.

Mr Breyer has remained quiet about his plans, at least publicly.

His last comment on the topic of retirement was made to Slate’s Dahlia Lithwick in an interview published in December.

“I mean, eventually I’ll retire, sure I will,” Mr Breyer said.

“And it’s hard to know exactly when.”

President Joe Biden already has pledged to name the first black woman to the court, if he gets the chance.

Among the names being circulated are California Supreme Court Justice Leondra Kruger, US District Court Judge Ketanji Brown Jackson and US District Court Judge Michelle Childs.

She is a favourite of Representative James Clyburn who made a crucial endorsement of Mr Biden just before the state’s presidential primary last year.

Mr Breyer’s departure would not do anything to change the conservatives’ 6-3 edge on the Supreme Court.

Republicans firmed up and expanded conservative control of the court during Mr Trump’s presidency.

First, they refused to consider Mr Obama’s nomination of Merrick Garland, after Justice Antonin Scalia died in 2016.

Mr Trump picked Justice Neil Gorsuch, 53, for the seat less than two weeks after he took office.

Anthony Kennedy’s retirement in 2018 and Ms Ginsburg’s death in September led to pitched confirmation battles that ended with Justice Brett Kavanaugh, 56, and Ms Barrett, 49, on the court.

But while the ideological make-up would stay the same, Mr Breyer’s retirement would allow Mr Biden to rejuvenate the liberal side of the court, where Justice Sonia Sotomayor is 66 and Justice Elena Kagan is 60.

If Mr Breyer steps down, Clarence Thomas, 72, would be the court’s oldest justice.

Ms Ginsburg maintained a steely, though ultimately mistaken, confidence that Democrats would retain the White House in 2016.

The US Supreme Court has the last word on many issues including abortion law and same-sex marriage.