That sound you hear is Democrats in Washington and across the country letting out a sigh of profound relief: Associate Justice Stephen Breyer is retiring in June, at the end of the US supreme court’s current term. News of the 83-year-old’s choice to step down broke on Wednesday – evidently a little earlier than the man himself would have liked – giving Joe Biden his first opportunity to fill a vacancy on the nation’s highest court.

The decision from Breyer ends months of speculation and a determined pressure campaign to convince the ageing liberal justice to retire while Democrats still held both the White House and the Senate, that rare and precarious circumstance that is now required for any Democratic president to see his federal court nominees confirmed. Breyer’s decision to step down this summer gives the Democrats a narrow window to appoint his replacement before they are expected to lose control of the Senate in the November midterms.

Breyer’s retirement, after nearly 30 years as a justice, will not change the balance of power on the supreme court, which has heaved dramatically rightward since Justice Anthony Kennedy chose to retire under Donald Trump in 2018. Nor will his exit mitigate what are likely to be ruinous outcomes in this term’s major rulings, which include the hateful Dobbs v Jackson, the case that is almost certain to overturn Roe v Wade. The benefits of his timely exit aren’t so much ameliorative as preventive: because he has retired under a Democratic trifecta, he has ensured that the supreme court’s conservative 6-3 supermajority will at least stay 6-3, and not become and insurmountable 7-2. But the extremist makeup of an increasingly maximalist rightwing court will continue.

What his retirement does bring to an end is a long legal and political career of the kind that has since become unfeasible. Breyer’s early career was marked by the industrious bipartisanship of the latter 20th century, and he helped shape that era’s neoliberal consensus.

When he was young, Breyer was a legal academic at Harvard – read any biography of a federal courts judge and the words “legal academic at Harvard” are likely to appear –and he wrote inventively about the prerogatives of executive agencies, a field known as administrative law. He favored deregulation, and took several leaves of absence from teaching throughout the 1970s to work as a special counsel to Democrats in the US Senate; among his accomplishments there was shepherding the deregulation of the airline industry.

He gained a reputation for friendliness and a willingness to negotiate, and as this was in keeping with the social norms of Washington at the time, he was close with a number of Republicans. His children played with the children of the segregationist Republican senator Strom Thurmond. This closeness with men on the other side of the aisle paid off: when President Clinton nominated Breyer to the supreme court in 1994, he was confirmed 87 to 9.

On the court itself, Breyer exerted his influence primarily in conference, attempting to extract compromises from his conservative colleagues and to cultivate their more moderate impulses. His colleagues on the left, Ruth Bader Ginsburg and later Sonia Sotomayor, took up the role first crafted by Thurgood Marshall, and wrote passionate dissents to conservative rulings that were meant to sway the public as much as the legal community. This was not Breyer’s style; he was nearly always speaking to other lawyers, not to lay people. We don’t know how much this worked – the justice’s conferences are confidential – but it is entirely possible that as the court shifted right over the course of his tenure, it was Breyer whose private arguments helped slow its lurch.

But as the court and the nation became more polarized, Breyer had come to seem out of place. His commitment to persuasion was no match for a 6-3 court packed with conservative ideologues; his passionate belief in legislative power did not fit with the realities of a deadlocked and dysfunctional Congress that increasingly delegated policymaking power to the judiciary. His questions – always famous for their long-windedness and convoluted structure – devolved into meandering soliloquies, and on the audio broadcasts of the court’s oral arguments, his liberal colleagues Elena Kagan and Sonia Sotomayor could often be heard trying to nudge him towards conclusion or clarify his point. It was obvious that he was from another time, and that time has now ended. The best thing he could have done for the country was go, and it is to his credit that he did.

What comes next? On the campaign trail, candidate Biden promised to appoint a Black woman to the court, and the likeliest candidate is Ketanji Brown Jackson, a former Breyer clerk who has the justice’s blessing and whose promotion to the DC circuit court of appeals last June was seen as a stepping stone to succeed her former boss. She is 51, and could serve on the court for decades.

But, if she is appointed, the institution that awaits Judge Brown Jackson is less collegial and less dignified than the one that welcomed Breyer. Despite the increasingly laughable protestations of its conservative wing, the supreme court has become an all but nakedly political body, frequently warping the law in bizarre and inventive ways to ensure outcomes that align with Republican priorities. They are going to dispose of abortion rights this year. Affirmative action is set to be dismantled. Voting rights have already been shockingly eroded, and the conservatives seem intent on interpreting religious freedom rights for Christians in whichever way can secure the maximum injury and indignity for everybody else.

Increasingly, the impression left by the justices themselves is one of vain and petty figures, fixated on their own PR, attempting to maintain the solemn mystique of an institution that has long since lost it. Who would want to join such a workplace? Perhaps Judge Brown Jackson, if she does indeed become the nominee, deserves not only our congratulations, but also our condolences.

• Moira Donegan is a Guardian US columnist