Something is rotten in the state of the Animal Farm, and it's not the dead sheep from the battle.
Mollie has been cavorting with one of the men on the neighboring farms in return for frivolities like sugar and ribbons. (Hey, we get it.)
Then she abandons the farm altogether. Oops.
Snowball and Napoleon start fighting with each other like two bullies on a playground arguing about who's bigger and who should be captain of the dodge ball team.
Snowball's speeches are better, but Napoleon does this clever campaigning business in the downtime between animal votes: when Snowball makes plans for a windmill for the farm, Napoleon pees on them.
Literally, he actually pees on the plans. Or "urinates," as Orwell so delicately puts it. We're not kidding.
Benjamin pops back up again to say that life is terrible either way, windmill or no windmill. Snowball and Napoleon give speeches about the windmill; Snowball's is superior. But before the vote, Napoleon brings in his private army of puppies, now all grown-up and tooth-baring and vicious, and they chase Snowball out of the farm. Napoleon wins by default.
Or by brute force, depending on your point of view.
Once he's in charge, Napoleon abolishes the meetings. Squealer makes him seem like a god by "explaining" things to the dumber animals.
Oh, and then Napoleon decides to build the windmill after all. How convenient.