The majority of vocal American Creationists are Christians and use the word Evolutionist to demonize evolution as some sort of false religion. You just have to go to the Answers in Genesis website or the 'science' section of any Christian Bookstore to see this in the works of men like Ken Hamm.
Most of the Christian Creationists I have met feel that their entire religion falls apart if the stories of Genesis are not literally true.
Most evolutionary scientists I know don't believe biology falls apart if Darwin's theory is proved incorrect they would just try to find a better theory.
Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring.
--Carl Sagan, 1934-1996