The argument that we should teach both creationism and evolution in public schools has been the fundamentalist argument since 1968, when the Supreme Court ruled that states can't ban the teaching of evolution. If you can't ban evolution, maybe you can neutralize it with a dose of Biblical literalism in biology class. But that strategy was also ruled an unconstitutional infringement of the Establishment Clause by the Supreme Court in 1987. Palin apparently disagrees with this decision (although it's doubtful that she knows of it):

COURIC: Should creationism be allowed to be taught anywhere in public schools? Gov. PALIN: Don’t have a problem at all with kids debating all sides of theories, all sides of ideas that they ever–kids do it today, whether it’s on paper in a curriculum or not. Curriculums also are best left to the local school districts, instead of big brother, federal government, telling a district what they can and can’t teach.

This isn't just unconstitutional, it's bad pedagogy. In the words of Scientific Blogging's own Massimo:

Learning critical thinking is not a matter of being exposed to a “fair and balanced” view of everything and be told “you decide.” Rather, it proceeds through learning about logic, about assessing evidence, and about the many ways in which human senses and reasoning abilities can fail us if we are not on guard.