The Supreme Court’s decision on Friday not to fast-track consideration of former President Donald J. Trump’s claim that he is immune to prosecution on charges of plotting to overturn the 2020 election was unquestionably a victory for Mr. Trump and his lawyers.

The choice by the justices not to take up the issue now — rendered without explanation — gave a boost to the former president’s legal strategy of delaying the proceedings as much as possible in the hopes of running out the clock before Election Day.

It is not clear, however, that the decision holds any clues to what the Supreme Court might think of the substance of his immunity claim. And the degree to which it pushes off Mr. Trump’s trial will only be determined in coming weeks as the clash over whether he can be prosecuted plays out in the federal appeals court in Washington — and then perhaps makes its way right back to the justices.

How the Supreme Court handles the case at that point could still have profound implications, both for whether the federal election interference indictment will stand and for whether Mr. Trump might succeed in pushing a trial past the election, when, if he wins the presidency, he could order the charges to be dropped.

Here is a look at what’s ahead.

What issue is Mr. Trump appealing?

Mr. Trump is attempting to get the entire indictment against him tossed out with an argument that has never before been tested by the courts — largely because no one else has ever made it this way. He is claiming that he is absolutely immune to criminal prosecution on the charges of election interference because they stem from acts he took while he was in the White House.

Judge Tanya S. Chutkan, who is handling the underlying case in Federal District Court in Washington, rejected that claim earlier this month in a decision that found there was nothing in the Constitution or American history supporting the idea that the holder of the nation’s highest position, once out of office, should not be subject to the federal criminal law like everybody else.

Mr. Trump appealed the decision to the first court above Judge Chutkan’s: the U.S. Court of Appeals for the District of Columbia Circuit.

But fearing that a protracted appeal could delay the case from going to trial as scheduled in March, Jack Smith, the special counsel who filed the indictment, made an unusual request to the Supreme Court: He asked the justices to step in front of the appeals court and consider the case first to speed up the process and preserve the current trial date.

On Friday, in a one-sentence order, the Supreme Court turned down Mr. Smith’s request.

Where will the case be heard now?

The appeals court in Washington will hear the immunity matter. In fact, the court will do so on a schedule that is extremely accelerated by judicial standards.

A three-judge panel of the court — made up of one judge named by President George H.W. Bush and two appointed by President Biden — has ordered all of the briefs in the case to be turned in by Jan. 2. It has set a hearing for oral arguments on Jan. 9.

In a sign of how quickly the panel is moving, the judges told Mr. Trump’s lawyers to turn in their first round of court papers on Saturday, two days before Christmas. Mr. Smith’s team has been ordered to submit its own papers on the following Saturday, the day before New Year’s Eve.

What happens after the appeals court rules?

If the appeals court decides in Mr. Trump’s favor, Mr. Smith’s office would almost certainly challenge the loss in front of the Supreme Court, assuming the justices agreed to hear it.

But the more likely scenario is that the three appellate judges rule against Mr. Trump, rejecting his claims of immunity.

At that point, he could seek to have the entire circuit court hear the appeal — a move that, if nothing else, would eat up more time. If the full court declined to take the case or ruled against him, he would likely ask the Supreme Court to step in for the second time.

What happens if it goes back to the Supreme Court?

In theory, the Supreme Court could decline to take up the immunity matter if Mr. Trump loses and simply let the appeals court ruling stand. That option could be appealing to the justices if they want to avoid stepping directly into a highly charged political issue — just one of several they are likely to confront in coming months that could have a bearing on Mr. Trump’s chances of reclaiming the White House.

Were that to happen, the case would go back to Judge Chutkan and she would set a new date for trial. Her handling of the case so far suggests that she would move the proceedings along at a rapid clip.

If, however, the Supreme Court were to take the case, the justices would have to make another critical decision: how fast to hear it. It is possible they could consider the case quickly and return a ruling on the immunity issue by — or even well before — the end of their current term in June.

But Mr. Smith has expressed concern in filings to the court that the justices might not be able to complete their work before the end of this term. If they do not, the case would drag into the next term, which does not get underway until October, too late to resolve before Election Day.

What does all of this mean for the start of the trial?

If the appeals court returns a quick decision against Mr. Trump and the Supreme Court lets that decision stand, the trial might be delayed, but perhaps only by a matter of weeks. Under this scenario, it is conceivable that the case could go in front of a jury by April or May, well before the heart of the campaign season.

If the Supreme Court takes the case and hears it on a fast-tracked schedule, the trial could be delayed for somewhat longer — perhaps by a matter of months. That would mean a trial could be held over the summer, a fraught possibility given that the Republican nominating convention is in July and that Mr. Trump, assuming he is the party’s nominee, could be kept from doing much traditional campaigning for the duration of the trial.

But if the Supreme Court takes the case and follows a leisurely pace in considering it, there might not be a trial at all before the general election in November. In that case, voters would not have the chance to hear the evidence in the case against Mr. Trump before making their choice — and a President Trump could choose to make sure they do not get the chance after the election either.