Or just:

Until around 1990 I believed, with most of my friends, that on a scale of evil from 0 to 10 (the worst), [$POLITICAL_BELIEF] scored around 7 or 8. Since the recent revelations I believe that 10 is the appropriate number. The reason for my misperception of the evidence was not an idealistic belief that [$POLITICAL_BELIEF] was a worthy ideal that had been betrayed by actual [proponents of $POLITICAL_BELIEF]. In that case, I would simply have been victim of wishful thinking or self-deception. Rather, I was misled by the hysterical character of those who claimed all along that [$POLITICAL_BELIEF] scored 10. My ignorance of their claims was not entirely irrational. On average, it makes sense to discount the claims of the manifestly hysterical. Yet even hysterics can be right, albeit for the wrong reasons. Because I sensed and still believe that many of these fierce [opponents of $POLITICAL_BELIEF] would have said the same regardless of the evidence, I could not believe that what they said did in fact correspond to the evidence.