Robert Gillespie, a lawyer in Richmond who is the head of the Monticello Association, which includes the descendants of Jefferson's two daughters, said, ''We've always agreed with mainstream historians that Jefferson wouldn't have fathered Sally Hemings's children.'' But, Mr. Gillespie said, the DNA results are ''changing my attitude.''
Mr. Gillespie said he had always believed that ''Jefferson would have shown the second set of children love and affection just as he did the first set. Apparently he was a product of the 18th century, and had a double standard.''
Dr. Ellis, author of ''American Sphinx: The Character of Thomas Jefferson,'' (Knopf, 1997), and other Jefferson scholars like Dumas Malone have long said that Jefferson did not have a relationship with Hemings. Dr. Ellis once dismissed the possibility as ''a tin can tied to Jefferson's reputation.''
Now, he said, the DNA tests have changed his mind. ''This evidence is new evidence and it seems to me to be clinching,'' he said. Dr. Ellis said circumstantial evidence, including a quotation attributed to another of Hemings's sons, James Madison, also pointed to a liaison. ''It includes the timing of her pregnancies, the physical resemblance of her children to Jefferson, and Madison saying late in life that his mother told him.''