The accusation on Monday by Senator Hillary Rodham Clinton’s campaign that Senator Barack Obama recently plagiarized a passage from a speech delivered two years ago by a friend has opened a door to charges and countercharges about borrowed phrases and unattributed inspiration in the 2008 campaign.

But it also revived questions raised in 1993 about whether President Bill Clinton, in his Inaugural Address, borrowed references to springtime from two sources without crediting them at the time.

Mr. Clinton began his inaugural by proclaiming: “Today we celebrate the mystery of American renewal. This ceremony is held in the depth of winter. But, by the words we speak and the faces we show the world, we force the spring. A spring reborn in the world’s oldest democracy, that brings forth the vision and courage to reinvent America.”

A few days earlier, the president-elect said that in drafting his address he had drawn on a number of sources, including a four-page outline by the Rev. Timothy S. Healy, president of the New York Public Library. Elaborating a decade later in his autobiography, Mr. Clinton recalled that he was dissatisfied with the latest draft of his address, but added:

“I did like one passage, built around the idea that our new beginning had ‘forced the spring’ to come to America on this cold winter day. It was the brainchild of my friend Father Tim Healy, former president of Georgetown University. Tim had died suddenly of a heart attack while walking through Newark airport a few weeks after the election. When friends went to his apartment, they found in his typewriter the beginning of a letter to me that included suggested language for the inaugural speech. His phrase ‘force the spring’ struck all of us, and I wanted to use it in his memory.”