WASHINGTON — The Supreme Court announced on Thursday that it would decide whether Congress may see parts of the report prepared by Robert S. Mueller III, the special counsel who investigated Russian interference in the 2016 election.
As a practical matter, the move means that the full report will almost certainly not be made available before the 2020 election, if at all. In May, the court blocked release of the report while the appeal moved forward.
The court will probably hear arguments in the case in the late fall, after the election, and issue its decision next year.
The case arose from a request by the House Judiciary Committee for grand jury materials that the Justice Department had blacked out from the report provided to Congress.
The House told the justices that it sought information about whether President Trump had obstructed justice, a topic on which Mr. Mueller declined to reach a conclusion.
“These redactions bear on whether the president committed impeachable offenses by obstructing the F.B.I.’s and special counsel’s investigation into Russian interference in the 2016 election and his possible motivations for doing so,” a House brief said.
“The committee’s impeachment investigation related to obstruction of justice pertaining to the Russia investigation is ongoing,” the brief said.
Indeed, the brief said, new areas of inquiry have arisen, including the Justice Department’s request for leniency in the sentencing of Roger J. Stone Jr., a friend of Mr. Trump’s who was convicted of witness intimidation and perjury, and the department’s request to dismiss its case against Michael T. Flynn, Mr. Trump’s first national security adviser, who had twice pleaded guilty to lying to investigators.
“The committee’s investigation continues today and has further developed in light of recent events,” the House’s brief said. “For example, the committee is investigating the possible exercise of improper political influence over recent decisions made in the Roger Stone and Michael Flynn prosecutions, both of which were initiated by the special counsel.”
In March, a three-judge panel of the United States Court of Appeals for the District of Columbia Circuit ruled that the materials must be released to help Congress consider whether to conduct impeachment proceedings. That disclosure was authorized by the Federal Rules of Criminal Procedure, the panel ruled, which contain an exception to grand jury secrecy rules for materials to be used “preliminary to or in connection with a judicial proceeding.”
The panel was divided on other issues in the case, but it agreed that an impeachment trial was a “judicial proceeding” for purposes of the rule.
Historical practice supported the ruling, Judge Judith W. Rogers wrote for the majority.
“Federal courts have authorized the disclosure of grand jury materials to the House for use in impeachment investigations involving two presidents and three federal judges,” Judge Rogers wrote. “It is only the president’s categorical resistance and the department’s objection that is unprecedented.”
In particular, Judge Rogers noted, Judge John J. Sirica in 1974 “ordered the disclosure of the grand jury report and accompanying materials to be delivered to the House Judiciary Committee, which was then engaged in an impeachment investigation of President Richard M. Nixon.”
Lawyers for the House said that order was part of an unbroken series of precedents. “To our knowledge,” they said, “no court has ever turned down a request for grand jury materials by Congress in connection with an impeachment.”
The House brief argued that the Constitution considered an impeachment trial to be a judicial proceeding, quoting its words: “the Senate shall have the sole power to try all impeachments”; “when the president of the United States is tried the chief justice shall preside”; “no person shall be convicted without the concurrence of two thirds of the members present.”
One of Mr. Trump’s lawyers at the impeachment trial, Ken Starr, made the same point, the brief said. “We are not a legislative chamber during these proceedings,” Mr. Starr said. “We are in court.”
In urging the Supreme Court to block the release of the report, Solicitor General Noel J. Francisco said the exception for judicial proceedings referred to court proceedings and not to impeachment trials.
He said the appeals court’s “historical examples” were “of questionable probative value because in each instance D.O.J. supported disclosure of the requested materials.” The Justice Department, he wrote, “has reconsidered that position.”
Lawyers for the House urged the justices to reject the department’s new position in the case, Department of Justice v. House Committee on the Judiciary, No. 19-1328.
“The decision below,” the House’s brief said, “was plainly correct to reject the newly developed position that D.O.J. has advocated here, after decades of taking the opposite view that Congress can indeed legally obtain grand jury materials in connection with impeachment proceedings.
The House brief said the grand jury materials would be kept confidential under protocols established by the committee.
“These protocols, which are similar to those used to protect grand jury and other confidential materials during the Nixon impeachment investigation, limit staff access to grand jury material; require storage of such material in a secure location; and provide that such material may not be publicly disclosed absent a majority vote by the committee,” the brief said.
Mr. Francisco called those protocols inadequate.
“Once the government discloses the secret grand jury records, their secrecy will irrevocably be lost,” he wrote. “That is particularly so when, as here, they are disclosed to a congressional committee and its staff. Indeed, as respondent acknowledged below, its own procedures will allow it to release these grand jury materials to the public by a simple majority vote of the committee (not even the full House).”