Characterize Snowball as a leader in "Animal Farm".

Snowball is a pretty popular leader on Animal Farm.  (In terms of the book's allegorical references, he represents Leon Trotsky.)  Snowball devises several plans for the future of Animal Farm, most notably his plans for the windmill, which sparks a debate amongst the animals.  Just as Snowball begins to gain too much popularity, Napoleon has him exiled from the farm, never to be seen again.  Typically, Snowball is seen as the better of the two possible leaders (himself and Napoleon, who represents Joseph Stalin).  Howver, both pigs step up to try to seize power once Mr. Jones is overthrown, and both do abuse power fairly early on.  For example, they partake in the eating of the windfall apples by the pigs, justifying it because they are the brain workers of the farm and need better food than the other animals.