Days before the presidential election, Chief Justice John Roberts extended a rare “courtesy” to his four liberal colleagues on the Supreme Court: He provided the needed fifth vote to temporarily spare an Alabama inmate from execution.

Roberts said he didn’t believe the case met the stringent standards for a stay. But because four other justices did, he joined them.

“To afford them the opportunity to more fully consider the suitability of this case for review, ... I vote to grant the stay as a courtesy,” Roberts wrote in the Nov. 3 late-night order sparing Thomas Arthur’s life for now.

Perhaps the move was a sign of comity in the midst of a divisive election season, Bloomberg’s Greg Stohr wrote. In August, a similar courtesy was extended in a high-profile transgender rights case ― that time a liberal justice joined the four conservatives. For a moment, it seemed as if the Supreme Court was trying to rise above its differences.

But courtesy fell apart late Thursday. In quick succession, the Supreme Court granted, denied, granted and then again denied last-minute requests to halt the execution of another Alabama inmate, Ronald Smith.

Joshua Roberts/Reuters Chief Justice John Roberts was "courteous" in one death penalty case but not in the next.

The most notable order came earlier in the evening. To that first denial of a stay, four justices — Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan — added a sentence noting that they would have temporarily spared Smith, presumably so they could have more time to consider the merits of his argument about the constitutionality of Alabama’s death sentencing system. This time, however, Roberts didn’t join them.

So Smith’s lawyers submitted two more petitions, alleging a double standard. In one of them, they said the Supreme Court’s “inconsistent practices ... in capital cases clash with the appearance and reality both of equal justice under law and of sound judicial decision-making.”

In the other, the lawyers seemed to call out Roberts directly ― for being courteous in the Arthur case, which is still pending, and not in their client’s case.

“For a fifth courtesy vote to be permitted to grant Mr. Arthur a stay of execution but for this Court to fail to do so on Mr. Smith’s behalf is arbitrary action that violates the Due Process Clause and the Equal Protection Clause,” the lawyers wrote. “There is no rational basis for the Court to take such action.”

One of those two petitions was briefly granted ― essentially to give the justices time to think ― and then both were almost as quickly denied. Late Thursday night Alabama executed Smith, who had been convicted of killing a store clerk in 1994.

“Smith heaved and coughed for 13 minutes during the 30-minute-long execution,” The Associated Press reported. “He clenched his fists and raised his head during the early part of the procedure.” Another Alabama reporter present at the execution observed that Smith’s “left eye also appeared to be slightly open.”

Leigh Vogel/Getty Images Justice Sonia Sotomayor was troubled that Alabama judges keep overriding the will of the jury in death penalty cases.

There’s a significant chance that Smith’s death sentence ― if not the method of execution itself ― was unconstitutional. Alabama is alone in the nation in allowing judges to condemn defendants to death even after juries have recommended life imprisonment instead. A jury, on a 7-5 vote, had recommended a life sentence for Smith.

But the judge thought otherwise and gave him death.

Justice Sotomayor, pointedly dissenting three years ago in a related dispute, listed Smith’s case on a chart of 95 “life-to-death” judicial overrides in Alabama. She suggested such overrides are “constitutionally suspect.”

Why do Alabama judges show this “distinctive proclivity” for reaching harsher sentences than the jury recommends, Sotomayor asked. “The only answer that is supported by empirical evidence is one that, in my view, casts a cloud of illegitimacy over the criminal justice system: Alabama judges, who are elected in partisan proceedings, appear to have succumbed to electoral pressures,” she wrote.

In January, the Supreme Court declared a similar judge-centric system in Florida unconstitutional. But Alabama is still holding out. In September, the state’s highest court found no conflict between that January decision and the state’s own practice of allowing judges to contradict jurors on the ultimate question.

Perhaps the courtesy vote was a one-time experiment, and for some reason unknown to us, it has been deemed a failure. University of Chicago law professor William Baude

The Arthur case could change things for Alabama’s capital defendants. At their private conference on Friday, the justices were slated to consider whether to give his case a full review.

As for the mystery of why one inmate received a courtesy reprieve and another one didn’t, we’ll likely never know.

University of Chicago law professor William Baude, who clerked for Chief Justice Roberts, pondered several scenarios for what may be happening behind the scenes. Some theories are “more troubling than others,” he wrote in The Volokh Conspiracy blog on Friday. But one stood out.

“Perhaps the courtesy vote was a one-time experiment,” Baude wrote, “and for some reason unknown to us, it has been deemed a failure.”