The theme of Animal Farm by George Orwell?
In the story, the animals ran the humans off the farm, saying
that all animals would be equal in the sense of having equal rights
in the new society. The pigs took over and ended up being like the
huymans had been before.
This is symbolic of people who lead a revolution or come into
power after a revolution, and turn out to be as bad as the leaders
that the revolution overthrew.