Style has to do with the way in which ideas are believed and advocated rather than with the truth or falsity of their content.
Richard Hofstadter (1916–1970) American historian and intellectual
“The Paranoid Style in American Politics,” Herbert Spencer Lecture, Oxford (Nov 1963)
(Source)
Reprinted in Harpers (Nov 1964).Often misattributed to Douglas Hofstadter.
Many thanks to Glen Worthey for pointing out I was one of those folk who had made that misattribution.