Eighty years ago this month, in the sweltering heat of a courtroom in Dayton, Tennessee, the right of a local 24-year-old school teacher, John Scopes, to teach the theory of evolution was the subject of an extraordinary trial that captivated the world.
It seems the ghost of John Scopes has still not been laid to rest. In 20 US states, most vigorously in Kansas, the issue of how to teach children about the origins of our species is still very much alive. But, refining their case, opponents of natural selection have moved to new ground. Under the mantle of "academic freedom", they argue that natural selection should be seen as one of two contesting alternative "theories", equally entitled to a place on the curriculum. Proponents of the theory of "intelligent design" say the complexity of the natural world is evidence of a guiding - and unseen - hand which has fashioned the way we are.
Now, to their delight, they have a new champion. President Bush on Monday told journalists that "both sides ought to be properly taught ... so people can understand what the debate is about". Debate? Really? To quote his distinguished predecessor, Woodrow Wilson, in 1922: "May it not suffice for me to say ... that, of course, like every other man of intelligence and education, I do believe in organic evolution. It surprises me that at this late date such questions should be raised".
It was the first time Mr Bush had backed the intelligent design cause as president, although he acknowledged that the issue was one for local decision. But yet again, in bowing to the religious right as he has also done on issues from stem-cell research to abortion and prayers in schools, the president has displayed a willingness to toy with Biblical fundamentalism. It is also reflected in his rhetoric of good and evil in dealing with terrorism.
Yet his views do reflect those of one third plus of the population which identifies with evangelical Christianity, the home of the electoral troops of the Republican Party.
But this is a slippery slope for an American school system already struggling to impart scientific education. The disingenuous case that essentially religiously-grounded theory should be granted the same status as well-established science - and natural selection, whether or not precisely as Darwin formulated it, is well-established science - undermines both science and potentially the constitutional separation of church and state. Yes, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Scopes was right.