Stephen Colbert isn't really a right-wing nutcase; he just plays one on TV. We can be reasonably sure that when he promoted the term 'truthiness' to denote a claim that feels right, even if there is no factual evidence to support it, he was making fun of certain right-wingers whose fact-checking is mostly internal; who will accept as true a story that fits with their worldview, regardless of the facts. Of course this is a universal human tendency, to which left-wingers are not immune, but Manjoo cites scientific studies that indicate that right-wingers are more susceptible to it (see below).

L'UMP scientifiquement moins scientifique ?