While opting to require businesses to provide health care coverage, Mrs. Clinton eschewed a mandate requiring that individuals obtain insurance, the approach that Mr. Obama would later adopt; she called that “politically and substantively a much harder sell than the one we’ve got.”

Image Representative John D. Dingell, Democrat of Michigan, was among those whose comments appeared in the memos. Credit... Bill Pugliano/Getty Images

Mr. Jennings advised her to “please try to avoid the word MANDATE” at all. They also worried that the Congressional Budget Office “is going to screw us” on its assessment of the plan and that abortion could be “a big problem,” similarly previewing events in the current administration.

At the time, Democrats came to doubt that the Clintons really understood Congress. Representative John D. Dingell, a powerful Michigan Democrat, thought the White House effort was in “disarray,” White House aides recorded. An unsigned memo warned: “We need strategic agreement among ourselves and between us and the Hill on timing and process. This can work, but it will come apart if we don’t get these pieces right.”

Mr. Jennings would later go on to work in Mr. Obama’s White House, and he is not the only one who appears in the documents. Among the Clinton aides mentioned in the memos are Rahm Emanuel, Gene B. Sperling, Steve Ricchetti, Bruce Reed and Victoria Nuland, all of whom served or still serve Mr. Obama.

The documents were posted online on Friday by the William J. Clinton Presidential Library in Little Rock, Ark., which is part of the federal government’s National Archives and Records Administration. They were the first batch of a broader set of 33,000 pages that could be made public over the next few weeks, documents that had been withheld despite past requests under legal exceptions that expired in January 2013.

The papers were processed by professional archivists, but then both Mr. Obama’s White House and Mr. Clinton’s office had to sign off before they were released. The papers were posted just days after Politico reported this week on the delay in disclosing them. A Clinton aide said his office approved releasing them within an hour of being told that Mr. Obama had.