The Supreme Court’s ruling on Monday in former US president Donald Trump’s 2020 election interference case makes it all but certain that the Republican will not face trial in Washington ahead of the November election.

In a 6-3 ruling, the justices said former presidents are shielded from prosecution for official acts but do not have immunity for unofficial acts.

The Supreme Court sent the case back to the lower court to determine whether core aspects of the indictment are unofficial versus official, and therefore potentially shielded from prosecution.

Here is what to know about the ruling and what comes next:

– The opinion

In the court’s majority opinion, Chief Justice John Roberts wrote that while “the president is not above the law” he also “may not be prosecuted for exercising his core constitutional powers”. Therefore, Mr Trump is “entitled to at least presumptive immunity from prosecution for his official acts”, Mr Roberts wrote.

The ruling means that special counsel Jack Smith cannot proceed with core allegations in the indictment — or must at least defend their use in future proceedings before the trial judge.

The justices, for instance, wiped out Mr Smith’s use of allegations that Mr Trump sought to leverage the investigative power of the Justice Department by ordering investigations into claims of voter fraud.

It does not matter, the justices said, if the requested investigations were based on sham allegations or based on an improper purpose. At the end of the day, the court said, “the president cannot be prosecuted for conduct within his exclusive constitutional authority”.

The justices said the lower court must “carefully analyse” whether other allegations involve official conduct for which the president would be immune from prosecution.

Among the issues for further analysis is Mr Trump’s relentless badgering of then-vice president Mike Pence not to certify the electoral votes on January 6 2021. The justices said it was “ultimately the government’s burden to rebut the presumption of immunity” in Mr Trump’s interactions with Mr Pence and sent the question back to US district court judge Tanya Chutkan.

– The fake electors scheme

The justices also directed additional fact-finding on one of the more stunning allegations in the indictment — that Mr Trump had participated in a scheme orchestrated by allies to enlist fake electors in battleground states won by Democrat Joe Biden who would falsely attest that Mr had won in those states.

The Trump team had argued that the selection of alternate electors was in keeping with Mr Trump’s presidential interest in the integrity and administration of the federal elections and cited as precedent an episode from 1876 in which the president Ulysses Grant sent federal troops to Louisiana and Mississippi to ensure that Republican electors got certified in those two cases.

The Smith team, by contrast, portrayed the fake elector scheme as a purely private action that implied no presidential duty.

The conservative justices in their majority opinion did not answer the question as to which side was right, instead saying that “determining whose characterisation may be correct, and with respect to which conduct, requires a close analysis of the indictment’s extensive and interrelated allegations”.

Unlike Mr Trump’s interactions with the Justice Department, the justices said, “this alleged conduct cannot be neatly categorised as falling within a particular presidential function. The necessary analysis is instead fact specific, requiring assessment of numerous alleged interactions with a wide variety of state officials and private persons”.

– Trial timing

The ruling makes it nearly impossible that a trial could be held before voters decide whether to send Mr Trump back to the White House.

No pre-trial preparations have taken place for more than six months since Judge Chutkan put the case on hold in December to allow Mr Trump to pursue his appeal. Judge Chutkan had indicated she is likely to give the two sides at least three months to get ready for trial once the case returns to her court.

That had left the door open to the case potentially going to trial before the election if the Supreme Court — like the lower courts — had ruled that Mr Trump was not immune from prosecution.

With the Supreme Court’s ruling, however, the case could be tied up for months with legal wrangling over whether Mr Trump’s conduct was official or unofficial.

– The dissenters

The three liberal justices — Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson — sharply criticised the majority’s opinion in scathing dissents. In her minority opinion, Ms Sotomayor expressed “fear for our democracy” and said the ruling wrongly insulates presidents as “a king above the law”.

The dissenting justices said the majority decision makes presidents immune from prosecution for acts such as ordering Navy seals to assassinate a political rival, organising a military coup to hold on to power or accepting a bribe in exchange for a pardon.

“Even if these nightmare scenarios never play out, and I pray they never do, the damage has been done. The relationship between the president and the people he serves has shifted irrevocably. In every use of official power, the president is now a king above the law,” Ms Sotomayor wrote.

In a separate dissenting opinion,Ms Jackson said the majority’s ruling “breaks new and dangerous ground.”

“Stated simply: The court has now declared for the first time in history that the most powerful official in the United States can (under circumstances yet to be fully determined) become a law unto himself,” Ms Jackson wrote.

– Trump’s other cases

Mr Trump was convicted in May of 34 felony counts in his hush money trial in New York and is scheduled to be sentenced on July 11. Each count of falsifying business records is punishable by up to four years behind bars, but there is no guarantee he will get prison time. Other possibilities include fines or probation.

It seems almost certain that Mr Trump’s two other criminal cases will not go to trial before the election.

An appeals court recently halted Mr Trump’s Georgia 2020 election interference case while it reviews the lower court judge’s ruling allowing Fulton County District Attorney Fani Willis to remain on the case. No trial date had been set in that case.