You can’t win if you fight science. After the Second World War, the intellectuals belonging to the Frankfurt school and other post-Bolshevik leftist groups developed the strategy of using Freudian psychoanalysis, which they touted as infallible science, to disarm their political opponents.
They created the image of a normal personality-type which was of a prototypical leftist—and they started using words like “deranged,” “racist,” “infantile,” “fascist,” “neurotic,” “nazi,” and “warmonger” to denounce those whose opinions did not fit the leftist personality-type. You had to be a leftist to be regarded as normal—if you were an independent thinker, then you faced the risk of being branded as abnormal. Since this branding was being done in the name of science, it was incontestable.
In the twenty-first century, this supposedly Freudian but essentially leftist method of analyzing and depicting personality-types has become the widely accepted norm in the intellectual establishment.