Shelden claims to be the mayor because he showed up first. Even though nobody ever attempts to take over, no one really sees him as the mayor, either. He is one of the first people the Hero meets in Passwall; he is seen heading up to the Gatekeeper with Felas Sarandas to watch a group of adventurers attempt to fight him. Besides some small tidbits of advice, he has very little to provide the Hero.