Eric Lander is not a "liberal historian". He is a research scientist who is head of the Whitehead Institute at MIT, which does cutting-edge research on DNA. Eric Lander is not trying to "rescue" Bill Clinton.
More importantly, this article claims that there are up to 25 persons from the Jefferson family who could have fathered Sally Hemming's children. Jefferson only had one brother who lived and no sons. So any other man with the same Y chromosome would have to come from a more distant branch of the family. But how would such a person have contact with Sally Hemmings over a period of many years? No one has given a plausible explanation of this. Thus there is actually only one other person other than Jefferson who could have fathered the children, his brother Randolph. But is has been shown that the dates when all these children were conceived coincides with dates when Thomas Jefferson had access to Sally Hemmings.
Given the DNA evidence, which should not be taken too far, but is nevertheless irrefutable, a lot of the arguments in this article are irrelevant.
You are assuming that we are talking about information from Sally Hemings' actual children. The Jefferson DNA samples all came from descendants of Jeffersons's paternal uncle Field Jefferson; the Hemings samples came from male descendants of Hemings generations removed from her children. So, actually, as one commentator pointed out about three years ago (in Chronicles magazine), there are not 25 possible candidates, but hundreds, not all of them white.
What that means is that there did not have to be ANY sexual connection between Sally Hemings and ANY Jefferson male, in order for some of her distant descendants to show Jefferson male DNA.
But how would such a person have contact with Sally Hemmings over a period of many years? No one has given a plausible explanation of this.
No such explanation is necessary. Your problem derives from your assumption that the hoax is true. They have never proven their case. For one example, the Hemings Party has always insisted that Thomas Woodson was her first child, conceived in Paris. Woodson was not the child of any Jefferson male. And reading the Hemings Party's claims in light of the DNA evidence, she was not monogamous (since they insist that Woodson was her child, which would mean that if there is anything to their claims, Hemings would have had to have at least one non-Jefferson lover). But then, having taken the trouble to read the article, you already knew that.
Thus there is actually only one other person other than Jefferson who could have fathered the children, his brother Randolph. But is has been shown that the dates when all these children were conceived coincides with dates when Thomas Jefferson had access to Sally Hemmings.
Not true. The claims are that Jefferson was at his estate when Hemings was impregnated. But there is no knowledge as to HER whereabouts, at the times she was impregnated. And not only did Jefferson's brother show up at Monticello at all of the times that Thomas was there, and regularly carouse with the slaves, but Randolph stopped spending time in the slave quarters at the same time that Sally stopped having children (because the widower Randolph had remarried). And eight different Jefferson males lived near Monticello.
Given the DNA evidence, which should not be taken too far, but is nevertheless irrefutable, a lot of the arguments in this article are irrelevant.
The only DNA evidence that even approaches irrefutability, is the evidence that Thomas Woodson was NOT the son of any Jefferson male. No DNA evidence has shown that Thomas Jefferson was the father of ANY of Sally Hemings' children.