I'm chief. I was chosen.
Why should choosing make any difference? Just giving orders that don't make any sense-
Piggys got the conch.
The rules! You're breaking the rules" (91)!
This dialogue between Jack and Ralph is showing the rebellion of Jack, and shortly after, the rest of the boys (except Simon and Piggy) leave the assembly with him. Things aren't looking good for the boys anytime soon.