Lynn Margulis argues that natural selection cannot provide a powerful enough evolutionary force to account for the punctuated equilibrium demonstrated in the fossil record. She proposes as an alternative that evolution is driven by changes in symbiotic relationships. I'm not a biologist, and I don't understand what exactly her theory means, so I'm not going to try to argue for or against it, but it got me thinking:
Evolutionary biologists cannot afford to let Margulis's theory become well-known and accepted as a mainstream theory, because that would create a rift in the pro-evolution camp, and creationists would be able to exploit this by combining Margulis's argument that natural selection cannot account for punctuated equilibrium with arguments by Neo-Darwinists against Margulis's theory to support their claim that evolution is false. This would be effective because many people would not understand that "we do not understand everything about how evolution works" does not imply "creationism is correct". Thus, many evolutionary biologists might feel that they have to be very careful to look like they do know everything about how evolution works. This could make it more difficult for them to spot aspects in which their assumptions about evolution are mistaken. Maybe the biggest damage caused by creationism is that it suppresses legitimate criticism of the current accepted models of evolution, besides spreading false information to the general public.
Again, I'm not arguing in favor of Margulis's theory in particular, but the statement "There exists at least one false fact about evolutionary biology that is accepted as true by a consensus of researchers in that field" seems fairly likely to be true.
Of course, it would be naive to assume that most people who give technically correct answers to such questions in polls have any real clue about the issues involved. They just answer the way they intuitively perceive to be high-status and ideologically correct; I'm sure most of them would easily change their opinion if these factors changed.
The primary reason people in the general public get worked up about evolution one way or another is ideological baiting and status concerns. The idea that it's somehow important for the common folk to have a correct view of scientific theories that have nothing to do with their regular business strikes me as rather absurd.