Most of the Trotskyist groups from the 1930s to the 1960s also adopted democratic centralism, but they infamously split all the time. Of course, Trotskyists are selected (amongst Leninists) as those willing to defect from the majority.
Trotsky was a total Slytherin, just see how many times he switched sides even before the revolution.
Update: This post has also been superseded - new comments belong in the latest thread.
The second thread has now also exceeded 500 comments, so after 42 chapters of MoR it's time for a new thread.
From the first thread: