What keeps the animals in Animal Farm from achieving the sort of equality that had been the original desire at the heart of their revolution against Mr. Jones
The animals are not able to maintain this equality as there are certain ones among them - most notably Napoleon - who want power for themselves. Napoleon is a ruthless manipulator who builds up an elite with himself at the top while other pigs like Squealer act as his agents to keep the rest of the animals under. Many of the animals like the mare Clover sincerely desire equality but are overpowered in the end by the strong-arm tactics and manipulation of the pigs, who want to keep control. The story is a fable of the Russian Communist revolution whose stated aim was a truly equal and just society but which degenerated into a totalitarian state with one man - Joseph Stalin - and his henchmen wielding absolute and ruthless control.