WASHINGTON — In June 1992, less than two weeks before the Supreme Court reaffirmed the constitutional right to abortion established in Roe v. Wade, Justice Anthony M. Kennedy sent a colleague some “late-night musings.”

“Roe was, at the least, a very close case,” Justice Kennedy wrote in the three-page memorandum, which included reflections on the power of precedent, the court’s legitimacy and the best way to address a cutting dissent.

The document is part of an enormous trove of the private papers of Justice John Paul Stevens released on Tuesday by the Library of Congress. They provide a panoramic inside look at the justices at work on thousands of cases, including Bush v. Gore and the 1992 abortion case, Planned Parenthood v. Casey.

The papers are studded with candid and occasionally caustic remarks, sometimes echoing current concerns about the court’s power and authority.

In the Casey decision, Justice Kennedy joined a controlling opinion with Justices Sandra Day O’Connor and David H. Souter that saved the core of the constitutional right to abortion established in Roe in 1973.

In June, the current Supreme Court overturned Roe and Casey after considering questions about precedent and the court’s legitimacy, coming to the opposite conclusion from Justice Kennedy.

There are other echoes of recent events in the papers of Justice Stevens, who served on the court for 35 years, retired in 2010 and died in 2019, at 99.

There was, for instance, an apparent leak, one that prompted Chief Justice William H. Rehnquist to write a stern note to all of the law clerks on June 10, 1992. The current issue of Newsweek, the chief justice wrote, “contains a purported account of what is happening inside the court in the case of Planned Parenthood v. Casey.”

The article, attributing its information to “sources” and “clerks,” said that “at least three of the nine justices are planning to draft opinions in Casey” and predicted, correctly, that the decision would be released on June 29.

Chief Justice Rehnquist admonished the clerks to follow a rule in the court’s code of conduct, which said, “There should be as little communication as possible between the clerk and representatives of the press.” He added, underlining the last three words: “In the case of any matter pending before the court, the least possible communication is none at all.”

Researchers will be studying the Stevens papers for decades, and only small glimpses were possible in a day’s scrutiny of a selection of them. But those glimpses made clear that the current turmoil at the court has historical analogues.

In 2000, for instance, when the court handed the presidency to George W. Bush in Bush v. Gore by a 5-to-4 vote, members of the majority wrote scathing private memos protesting what they called unduly harsh language in the dissents.

Justice Stevens’s dissent ended this way: “Although we may never know with complete certainty the identity of the winner of this year’s presidential election, the identity of the loser is perfectly clear. It is the nation’s confidence in the judge as an impartial guardian of the rule of law.”

In a memo to his colleagues on Dec. 12, 2000, the day the decision was issued, Justice Kennedy, who had voted with the majority, appeared wounded.

“The tone of the dissents is disturbing both on an institutional and personal level,” he wrote. “I have agonized over this and made my best judgment.”

He added, “The dissents, permit me to say, in effect try to coerce the majority by trashing the court themselves, thereby making their dire, and I think unjustified, predictions a self-fulfilling prophecy.”

Justice Antonin Scalia, who had also voted with the majority, said he was “the last person to complain that dissents should not be thorough and hard hitting.”

But he said he could not “help but observe that those of my colleagues who were protesting so vigorously that the court’s judgment today will do irreparable harm have spared no pains — in a veritable blizzard of separate dissents — to assist that result.”

At an earlier stage of the case, Justice Stephen G. Breyer, who dissented in Bush v. Gore, urged his colleagues to stay away from the dispute, recalling the role that Supreme Court justices had played on a commission created to resolve the contested presidential election of 1876.

“Rather than the court lending the process legitimacy, the process damaged the legitimacy of the court,” Justice Breyer wrote. “I doubt very much that our intervention would assure anyone that the process had worked more fairly. Rather, I fear that history could repeat itself, were we to intervene now.”

In statements after the Supreme Court’s recent abortion decision, Dobbs v. Jackson Women’s Health Organization, Justice Samuel A. Alito Jr. has said that attacks on the court’s legitimacy, as opposed to its reasoning, should be out of bounds.

In the 1992 memo containing his “late-night musings,” which was addressed to Justice Souter and copied to Justices O’Connor and Stevens, Justice Kennedy also reflected on the court’s legitimacy in the context of abortion.

He appeared troubled by aspects of Chief Justice Rehnquist’s dissent, which said public opinion should not affect the court’s work.

“You can fend off the chief,” Justice Kennedy told Justice Souter, “by stating that we are not concerned with preserving our legitimacy for our own sake but for the sake of the Constitution. Thus, when we speak of the principled character of our decisions, we mean that they are informed by precedent, logic and the traditions of our people, all with reference to our constitutional heritage.”

“We must be clear,” he went on, “that we are not guided by expediency, contemporary attitudes or our own morality.”

The newly released files cover the years up to 2005, when Chief Justice John G. Roberts Jr. joined the Supreme Court. They are filled with notes in Justice Stevens’s not always legible scrawl, marked-up briefs, draft opinions, vote tallies, memos among the justices, recommendations from clerks and all manner of other paperwork.

Before the new release, the most recent set of Supreme Court papers was from the files of Justice Harry A. Blackmun, who served through 1994 and died in 1999.

The only current member of the court featured in the new files is Justice Clarence Thomas. The remaining parts of Justice Stevens’s papers are scheduled to be released in 2030.

Kitty Bennett contributed research.