In episode 3 of Star Wars, as Anakin returns from the jedi temple to talk with Padmé, he says "I will not betray the republic". Yet, later he does exactly that.

First, Anakin opposes the jedi as they are trying to overthrow the democratically elected Palpatine. Later, the emperor basically reveals to Anakin that he orchestrated the whole rebellion which lead to the clone wars. Palpatine sends Anakin to Mustafar. On the planet, the separatist leaders expect his arrival and Anakin sees that as he meets them. As Anakin finds out about the games the emperor is playing, he doesn't seem to be bothered even though they show that the emperor should not be trusted.

Before his duel with Obi Wan, Anakin vocally opposes the idea of the republic and of democracy even though he realizes that will make him lose Padmé as well.

Why Anakin doesn't seem to care that the emperor is behind the clone wars? Why did he decide to team up with him despite of all this?