The real reason that Snowball is expelled from the farm is that Napoleon regarded him (perhaps correctly) as a dangerous rival. Snowball is intelligent, a gifted leader, and very popular among the other animals. He is the animal most responsible for working the teachings of Old Major into Animalism, and he has been a leader of the revolution since its beginnings. Snowball's relationship with Napoleon begins to sour after the Battle of the Cowshed, with Snowball, (based on Leon Trotsky) disagreeing with Napoleon (Stalin) on two important issues. One is whether the animals should attempt to spread revolution throughout the countryside, and the other is over the construction of a windmill. They have several debates, but Napoleon increasingly uses the sheep to drown out Snowball's speeches. With a public vote on the windmill looming, Napoleon uses his dogs to run Snowball from the farm. He becomes an imagined enemy for the animals, with Squealer always claiming that he is orchestrating a counter-revolution from the outside.