It was telling that even science-positive Republican candidate Jon Huntsman said that he "believed" in evolution, rather than, say, that he accepted it or appreciated its power to explain life's diversity. Then he qualified his statement with "Call me crazy," acknowledging that to accept mainstream science puts him outside the mainstream of his party.
Why should this debate rage in the political sphere when there's near universal acceptance among scientists that Darwin had the basic idea right 150 years ago? Political candidates don't get points in any party by denying atomic theory, or germ theory, relativity, or plate tectonics. Nor do people refer to these ideas as something that requires belief.
For one thing, evolution is personal. It offers a natural explanation for our own origins that's wildly different from the biblical story. And even more jarring for some, evolution showed we were molded from the same process that led to fish, frogs, and monkeys.
The rancor makes more sense in the context of its deep history, said Swarthmore biology professor Scott Gilbert. The roots of this disagreement go back to 19th-century Europe, where state-sponsored religions were taught as science, said Gilbert, who has degrees in both biology and religion.
After On the Origin of Species was first published in 1859, British scientist Thomas Huxley used it as a club to try to shatter the intellectual monopoly of the Anglican Church.
Back then, to teach at the prestigious Oxford or Cambridge Universities, a professor had to become a member of the Anglican clergy.
No Catholics, Jews, Muslims, or atheists need apply.
"You had to agree that nature was God's creation," Gilbert said, and the only people thought worthy of interpreting God's creation were those in the official state religion.
In Germany, biologist Ernst Haeckel fought a parallel battle with Lutheranism, which was so dominant that adherents to other faiths weren't allowed to become medical doctors there.
While Huxley coined the term agnosticism to define his own lack of belief, Haeckel made up his own religion, called Monism.
"This is, I think, where much of this whole science versus religion rhetoric comes from," Gilbert said. "It's basically science trying to break the monopoly of state religions."
Today the battles continue over the public role of America's dominant religion, Christianity. When candidates are asked about evolution, most jump quickly to the issue of teaching evolution in public schools, and whether the religious picture should be taught as well.
Rick Perry said schools in his state, Texas, teach both evolution and creationism. But they shouldn't be, since this isn't part of the teaching standards, said Josh Rosenau, programs and policy director at the National Center for Science Education in Oakland, Calif.
"The way he phrased it, it sounded like in Texas as a matter of policy we teach both," Rosenau said, but he argues that's not the case. Over the years, he said, creationists have inserted language into the teaching standards, such as "strengths and weaknesses" of evolution, and "examine all sides of the scientific evidence," which is not applied to other fields of science and could be used as "hooks creationists can work with."
More-direct creationist claims were included in supplements that some factions were trying to have added to textbooks this year, Rosenau said. But the Texas school board last month agreed to adopt only supplements with the established science, so as of now there's no official policy to teach creationism there.
By trying to cast doubt on the science, creationists attempt to leave room for the Christian viewpoint - not the creation stories of, say, the Navajo.
Gilbert sees the quest to insert creationism into science classes as a degradation of religion. Today, no religion can compete with science as a way to get at literal truths about the way the world works, he said. Its realm should be in wisdom, not knowledge.
Knowledge is being able to identify a tomato as a fruit, but wisdom, he said, is not putting them in a fruit salad. When Perry or Bachmann advocates teaching creationism as science, "they are making religion insipid, a one-dimensional parody."
It's also inappropriate to promote a single religion in the public sphere, said Timothy Thomson-Hohl, pastor of Ardmore United Methodist Church and an adjunct professor at Drexel, where he co-teaches a class on science and religion.
For him, there is a way to believe in evolution and still be a person of faith. Personally, he said, he's comfortable with evolution. But he agrees it's not a simple matter for Christians to accept all the implications of evolution.
Many Christians believe that Jesus saved mankind from the original sin committed by Adam and Eve, and this whole tapestry falls apart if you make the original couple into fictional characters.
"It's like pulling on a thread and the whole thing comes unraveled," he says. How do you cut out some aspects of the tradition to make way for science? "It's a complication for Christians," he said, but not one that can't be worked through.
On the other hand, there's no reason to fret that the popularity of creationism is causing America to lose technological prowess, said Gilbert. "I don't see any connection." People can be passably good engineers, chemists, computer programmers, or gadget-designers without necessarily understanding evolution.
But if evolution is not taught well, students get cheated out of understanding a crucial area of science. Gilbert questions whether even those who say they "believe" in evolution have been given the chance to fully appreciate the way it works and to evaluate the evidence.
One reason the debate keeps heating up is that on the evolution side, the science keeps advancing, encroaching into areas that had long been the realm of mythology. More details continue to fill in our picture of humanity's evolution from our common ancestor with chimps. We're even beginning to understand how inanimate matter became organized into the first living things.
For some, this comes as a threat, diminishing the role of a supernatural creator. For others, advancing knowledge only adds to the sense of wonder inspired by the natural world.
Contact staff writer Faye Flam at 215-854-4977 or email@example.com. Read her evolution blog at www.philly.com/evolution, or follow her on twitter @darwins_hellcat.