Menachem Butler, today, writes about Eugenio Zolli the chief rabbi of Rome who converted to Roman Catholicism after World War II. I don't know much about Zolli, but I do know that, in his discussion, Butler omits Zoli's signal accomplishment: by convertng he helped whitewash the crimes and misdeeds of Eugenio Pacelli, Pope Pius XII.
"How bad could Pius have been," argue Catholics, "if the chief Rabbi of Rome converted."
The statement demonstrates a profoud ignorance of the human mind, but there it is.
Anyone seeking additional information on Pacilli should read Hitler's Pope, or Papal Sins, both excellent volumes. And if you, too, are ignorant of Pacelli's crimes, ask in the comments.