Two poles of exclusion: ostracism and pariah-ness.
There has been a multi year effort in our department to ostracism the most senior and productive faculty.
As this is illegal and as the most senior faculty are also by far the most productive faculty, these efforts have stalled.
This has not stopped the gossip and rumor mill: a colleague at UCSF was quoted as saying the senior faculty were dead wood and "in the way." When this was made public the usual denials and back-tracking occurred.
So, the other tactic is to make people into pariahs. Jean-Claude Milner discusses this status in his book "Le Juif savant."
There is social exclusion and political exclusion. By creating these forms of pariah-ness the only open road is scholarship and thought. The record speaks for itself.