This comes from one "Jexpat" on Oregonlive, who was accused of "name calling" when he described the behavior of certain posters a disingenuous and delusional who calls himself "conservatype"
Here's the dictionary definition what's been on display:
de lu⋅sion:
Psychiatry. a fixed false belief that is resistant to reason or confrontation with actual fact. e.g.
a paranoid delusionNow, there several reasons why right wing types become delusional.
One is mental illness- Michele Bachmann (and it seems Glen Beck) present with clinical symptoms, which can be found in the diagnostic criteria of DSM IV-TR 297.1
Another is simply psychological weakness (and failure to critically think). Right wingers are so emotional invested in conclusions they already hold that they bypass cortical centers of reason altogether, in order to avoid cognitive dissonance (which is painful to confront). This is also known as confirmation bias.
More mundane reasons include gullibility, racism, and a condition we all recognize as "proudly ignorant and mean."
All of these conditions are refractory (stubborn) -but can be treated, provided patients recognize how dysfunctional they are to themselves and others- and have the courage to face up to their problems.
http://www.oregonlive.com/news/index.ssf/2009/09/text_of_obamas_speech_to_stude.html#preview