Mrs. Clinton said she hoped the House would hold further investigations by calling people like Donald F. McGahn II, the former White House counsel. She compared Mr. McGahn to John Dean, President Richard M. Nixon’s counsel, who became a critical witness in the Watergate scandal. And she repeated her contention that Russia’s hacking had tipped the election against her.

While the Mueller report found that no members of the Trump campaign “conspired or coordinated” with Russians to tilt the election, it established that “the Russian government perceived it would benefit from a Trump presidency and worked to secure that outcome, and that the campaign expected it would benefit electorally from information stolen and released through Russian efforts.”

Few members of Mr. Trump’s inner circle have had as much exposure to Mr. Mueller’s prosecutors as Mr. Kushner. He was one of the first senior officials summoned as a witness, sitting for an hour in the fall of 2017 for an interview focused on Michael T. Flynn, Mr. Trump’s former national security adviser, who is awaiting sentencing for lying to federal investigators about his ties to Russia.

Then, last April, Mr. Kushner was called back again for a nearly seven-hour interview that covered much of Mr. Mueller’s investigation, including Mr. Trump’s behavior in office. Both interviews are cited repeatedly in the report.

Mr. Kushner’s remarks on Tuesday drew an enthusiastic response from the president, who tweeted, “Great interview by Jared.” He received a polite, if low-key, reception at the conference, which brings together public figures named to Time’s list of the 100 most influential people in the world. He was interviewed by the magazine’s senior White House correspondent, Brian Bennett, who also pressed him on the timing of his long-awaited Middle East peace plan.

He said the administration planned to present it after Ramadan, the Muslim holiday that ends in early June. The plan has been basically ready since the beginning of the year, but the administration delayed the rollout for several months because of the election in Israel, which was a resounding victory for Prime Minister Benjamin Netanyahu, a close ally of Mr. Trump’s.

As he has in the past, Mr. Kushner declined to share details of the plan. But he pointedly ignored a question about whether it would call for an independent state for the Palestinians — a feature of American diplomacy for decades — and suggested that the “two-state solution” was a failed formula of the past.