It began with a whimper, and ended in a bang. Last Tuesday night, as the clock struck midnight, a booming silence engulfed the US supreme court in Washington – and with it an extreme new anti-abortion law was allowed to go into effect in Texas.

The court’s aggressive inaction – remaining quiet as SB 8 was enacted – overturned the constitutional right of more than 6 million Texas women to control their own bodies and punched a giant hole through the supreme court’s own groundbreaking 1973 ruling, Roe v Wade. The bizarre disappearing act of the court’s nine justices led to nationwide bemusement: how could the top judges in the land allow a pillar of American democracy to be toppled at dead of night, with barely any discussion, and without a single word of explanation?

“The court’s failure to rule on the request for an injunction before the Texas law took effect was a grave institutional failure,” said Kate Shaw, a law professor at Cardozo Law who co-hosts the Strict Scrutiny podcast. “The silence sent a clear message that states can act in ways that are flagrantly unconstitutional under settled law where abortion is concerned.”

One night later, also under cover of midnight, the court’s whimper burst into a full-blown explosion. By a majority of five votes to four, the rightwing core of justices – including all three of Donald Trump’s controversial appointees – refused to intervene to block the Texas law.

Their decision, unsigned and laid out in a single paragraph, left close observers of the supreme court shellshocked. Here was the highest court in the land willingly allowing the state of Texas to ride roughshod over its own legal authority by violating the constitutional right to an abortion that the court itself had established almost half a century ago.

“The court’s hostility to abortion has led it to approve a law that is not only plainly unconstitutional, but a threat to the social fabric and to the rule of law,” Shaw told the Guardian.

While Roe bans abortions after a fetus reaches viability at around 24 weeks, SB 8 imposes an effective six-week ban that would prevent up to 90% of all Texas terminations from going ahead. “The law is a blatantly unconstitutional ban on abortion around six weeks in pregnancy, before most people know they are pregnant. It violates nearly 50 years of Supreme Court precedent,” said the ACLU’s Brigitte Amiri, a member of the legal team that had petitioned the court to intervene and stop the Texas law.

The court’s extreme turn this week has already had a devastating impact on the women of Texas, with abortion clinics turning patients away. SB 8 encourages private citizens to act as vigilantes by suing anyone who helps a woman obtain care.

If the consequences for women are dire, the implications for the long-term health of American democracy are no less ominous. In her dissenting opinion, Sonia Sotomayor describes SB 8 as a “breathtaking act of defiance – of the constitution, of this court’s precedents, and of the rights of women seeking abortions”.

By stipulating that no state official could execute the new anti-abortion provisions, and by outsourcing enforcement instead to ordinary citizens, the Republican framers of SB 8 had played a dastardly trick on the US legal system. As Sotomayor explained, it was an audacious ploy designed to evade the scrutiny of federal courts by removing the accountability of state officials.

Despite the unsubtle nature of the ruse, the supreme court’s rightwing majority blithely went along with it. Sotomayor called her fellow justices’ decision “stunning”, and wrote: “Today, the court finally tells the nation that it declined to act because, in short, the state’s gambit worked.”

Stephen Vladeck, a professor of constitutional law at the University of Texas at Austin, warned that the majority’s willingness to play along with the antics of hyperpartisan state Republicans could have calamitous long-term consequences. “This is a court telling Republican legislators that tricks are fine, that shenanigans are fine – as long as we like the bottom line that those tricks and shenanigans produce.”

Vladeck points to a decision in April in which the same five rightwing justices – including Trump’s three appointees, Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett – did the exact opposite to what they did this week. In another unsigned order, issued similarly at dead of night, they moved this time to block the provision at hand.

In this instance, the five justices combined forces to foil the will of officials in California – a Democratic state – who were attempting to prevent the spread of Covid-19 by imposing restrictions on at-home gatherings. Same five justices, same late-night order, diametrically opposed outcome. Republicans get their way in Texas, Democrats are blocked in California. The contrast left little to the imagination.

That is the part that Vladeck said he was finding hardest to fathom. By being seen to operate in such overtly contradictory and partisan ways, the dominant rightwing group of justices runs the risk of existentially damaging the reputation and standing of the highest court.

“It is increasingly apparent that a majority of the justices are simply indifferent to what a large number of Americans think about the court as an institution,” Vladeck said. “Do they not appreciate that they are taking steps widely perceived to be harming their legitimacy or, even worse, do they just not care?”

The irony is that only three months ago, at the end of the 2020-21 term, many leading observers were commenting that the new court remade in Trump’s image had failed to have the extreme rightward thrust that had been widely predicted. As the New York Times’s supreme court correspondent, Adam Liptak, wrote, the “liberal members are having a surprisingly good run”.

It now seems that Liptak and other analysts may have been looking in the wrong direction. By focusing on the merits rulings of the court – the fully fledged cases involving oral hearings and expansive judgments – the pundits downplayed where the real action was happening: in the shadows.

The so-called “shadow docket” – in which emergency orders are issued in the dead of night with virtually no debate and exceedingly little public justification – has mushroomed in recent years. It now accounts for most of the court’s business, and as it grows it is increasingly dragging the nation’s most significant jurisprudence into the darkness.

The liberal justice Elena Kagan raised the shadow docket specifically in her dissent to Wednesday’s Texas decision. It was the first time that any member of the court had challenged head-on the untrammeled rise of the practice.

Kagan berated the rightwing majority for allowing the patently unconstitutional Texas law to go ahead after less than 72 hours’ thought and with minimal review of the evidence. She said the majority “barely bothers to explain its conclusion”.

All in all, she wrote, the events of this week were “emblematic of too much of this court’s shadow-docket decision-making – which every day becomes more unreasoned, inconsistent, and impossible to defend.”

The proliferation of unaccountable orders issued at midnight from a majority of justices who are willing to cooperate with the undisguised trickery of ideologically driven state Republicans hardly bodes well for the future of the supreme court, or America. When the new term starts next month, the court will be considering Dobbs v Jackson Women’s Health Organization, a case focusing on Mississippi’s law banning abortions at 15 weeks which has the potential to put the final nail in the coffin of Roe v Wade.

“The bloom is off the rose that this new supreme court is going to have any moderation,” Vladeck said. “No one who watches the court closely would put any money on the right to abortion looking the same at the end of this upcoming term as it does today.”