Among the communists, I think both types could be found, it is just that the more idealistic, moderate and anti-authoritarian people always lose out in those revolutions. An organized, amoral and unscrupulous minority has a big advantage over them. Classical liberalism suffers from the same issues, and systems designed by classical liberals also often get subverted by minority interests.
>Classical liberalism suffers from the same issues, and systems designed by classical liberals also often get subverted by minority interests.
Yes but in classical liberal states, when the minority interests subvert established norms, it very rarely leads down a path of mass bloodshed and wanton destruction. In heavily authoritarian communist revolutions, one mistake of letting the "more extreme" (because even the less extreme figures in these kinds of regimes tend to also be fanatics) reach power gives you a regime like Mao's or Stalin's. Even in less extreme examples, few people would call a government like Castro's preferable, or claim that if Trotsky had come to power, then repression and mass shooting would have ended in the USSR.
Beyond just ideology, the type of state institutions and their fundamental tendencies of respect for the rule of law (or a lack of this respect) are important factors in deciding how far the unscrupulous can go even if they do come to power.
This is why in a country like the U.S. with very stable liberal traditions and strong state institutions built with these traditions in mind (if imperfectly), having someone like a Nixon or Trump get into power gives results that are nowhere near as bad as they are when a Hitler, Castro, Mao or Lenin comes to power in a country with much weaker bulwarks of liberal history.
