Though, in the "some animals are more equal than others" environment of Wikipedia, there's a handful of powerful people (sometimes termed the "clique" or "cabal") who, if they decide that some banned user is Evil Incarnate, will promptly add to their Enemies List any admin that dares to unblock such a user, try to shame that admin into reversing the action, and agitate for the desysopping or banning of the non-groupthink-compatible admin if he/she resists that.
Can you give an example of a time when this has actually happened? Naming the admin and the person they unblocked?
I'm not claiming there is no cabal, that would be nonsense. Of course there is a cabal. The key thing that people miss is that there is more than one. The other common name is "groups of friends". There are lots of groups of friends on Wikipedia. Some of them contain quite powerful Wikipedians, and work to help their members. However, and most importantly, they do not all work together, and no one of them is all powerful. If one group of friends crosses the line, other groups and individuals will step in to stop them. A good example of this is MONGO - he had a strong group of friends that defended him at every turn, but once it got too bad, other people stepped in and stopped it. MONGO was eventually desysopped.
There are some very powerful cabals around, but none of them are all powerful. Most of the time, these cabals work to the benefit of Wikipedia. We usually ignore the times when they harm Wikipedia because they are quite minor incidents (they seem pretty major to those involved, I'm sure, but in "the grand scheme of things", it's not worth the hassle). However, when they cross the line people can, will and *have* stepped in.