The partisan and ideological polarization of American politics since the 1970s appears to have affected pubic opinion in striking ways. The American public has become increasingly partisan and ideological along liberal-conservative lines on a wide range of issues, including even foreign policy. This has raised questions about how rational the public is, in the broad sense of the public's responsiveness to objective conditions. Widespread partisan disagreements over what those conditions are-i.e., disagreements about the facts suggest that large proportions of the public may be perceiving the facts incorrectly. The facts in question are important enough that these partisan disagreements may translate into sub-optimal policy preferences and electoral decisions.