Democrats asked for summaries from interviews with Annie Donaldson, Mr. McGahn’s chief of staff; Hope Hicks, the former White House communications director; Reince Priebus and John F. Kelly, former White House chiefs of staff; Michael D. Cohen, Mr. Trump’s onetime fixer and personal lawyer; and Mr. Sessions, among others.
Democrats had also requested detailed notes taken by Ms. Donaldson about White House meetings and Mr. McGahn’s interactions with the president, as well as notes taken by Joseph H. Hunt, Mr. Sessions’s chief of staff when he was attorney general. Other documents in the narrowed request included a draft letter justifying the firing of James B. Comey as F.B.I. director, a White House counsel memo on the firing of Michael T. Flynn as national security adviser and other documents created by the White House.
Democrats referenced some of that evidence at Monday’s hearing as they marched through Mr. Mueller’s report.
“Professor McQuade, what purpose or function does note-taking serve for lawyers?” asked Representative Karen Bass, Democrat of California, referring to one of the witnesses, Barbara McQuade, a former United States attorney in Michigan.
Representative Ted Lieu, another California Democrat, said, “Let’s talk about Jeff Sessions’s recusal.”
Mostly, Democrats got what they were looking for.
“The obstruction described in the report created a risk to our national security,” Ms. McQuade said. “It was designed to prevent investigators from learning all the facts about an attack on our country.”
Republicans turned to their witness, John Malcolm of the conservative Heritage Foundation.
“While it is certainly true that no man, including the president of the United States, is above the law, it is equally true that the president occupies a unique position in our constitutional structure and that some laws apply differently to him and some don’t apply at all,” he said.