Okay, so have you ever wondered why a fairly large percentage of Americans believe that Iraq and Hussein were involved in the attacks on September 11, 2001? Although the Bush Administration shares a good deal of the blame, its deceit isn't the whole reason. Part of the reason has to do with the human brain. Consider the following quote from this article in the September 4, 2007 Washington Post:
The psychological insights yielded by the research, which has been confirmed in a number of peer-reviewed laboratory experiments, have broad implications for public policy. The conventional response to myths and urban legends is to counter bad information with accurate information. But the new psychological studies show that denials and clarifications, for all their intuitive appeal, can paradoxically contribute to the resiliency of popular myths.
This phenomenon may help explain why large numbers of Americans incorrectly think that Saddam Hussein was directly involved in planning the Sept 11, 2001, terrorist attacks, and that most of the Sept. 11 hijackers were Iraqi. While these beliefs likely arose because Bush administration officials have repeatedly tried to connect Iraq with Sept. 11, the experiments suggest that intelligence reports and other efforts to debunk this account may in fact help keep it alive.
This research puts politicians and public officials who face opponents who aren't afraid to lie in a bad situation. If they ignore the lie, then people might believe it is true who otherwise wouldn't believe it is true. Taking the lie on, however, by putting out facts refuting the lie might also contribute to the lie being better remembered by people who have heard it. It is a fascinating article and one that you might want to take the time to read.