Undoubtedly there are many in the church with strange idealogies. I wouldn't doubt but what the Vatican and Europe would have been more targeted than America, if it is true that a significant number of communists infiltrated the church.
I'm not sure how all the various factors and purveyors of change took root in America. Looking for a simplistic, one-size-fits-all answer doesn't work for me.
I can't find statistics, but most of the sex abuser priests were ~probably~ not converts. Most communists would have been raised outside the catholic faith.
There are some sinister characters in high places whom I suspect of skulduggery in the church, but their motives and methods vary. Bishop Hnilica comes to mind and that Marcinkus character.
Most of the problems with priests and/or bishops we can narrow down to willful disobedience to proper directives, homosexuals who cannot control their urges, heterosexuals who cannot control their urges, financial malfeasance, and alcoholism.
The least of my worries now are communists in the church.
The author subscribes to the communist theory, as do some others. I personally think it is too simplistic to blame it on the communists. Communism, as we have known it, is on the wane. Undoubtedly some new form of evil will arise and that's what we need to be on the lookout for.
Maybe we should blame it on the Democrats ;-).
I don't think the priests involved in these scandals would have been the sleepers. But their superiors almost certainly would have been. The sleepers would be circumspect in every way in order to avoid suspicion. But when they were consecrated and given their dioceses, they would have used what they knew to manipulate and mold as many clones as possible.