1) A system that can only stably support two parties at a time, leading to really weird combinations of issues under the two parties (imagine a world where voting for a "pro-life" party didn't also mean voting against a social safety net and for the death penalty, for instance—much saner, no?)

2) Propaganda. See any number of studies about people's perceptions of tax policy and various government programs, versus the reality of same. Some discrepancy would exist no matter what, but much of it is the result of deliberate misinformation.