Peter did an excellent job explaining how it all should work. In successful communities that does happen. Unfortunately I used to work in a city where I witnessed some of the worst behavior and decisions from elected officials.
This was because some of them only ran for the perceived status or to get one specific project done that directly benefited them or to get their kid hired by the city or take out a grudge against an employee. This makes it impossible for staff to continue to implement long range projects and ensure sustainability and success of the community. And because these elected officials publicly attack and ridicule staff, the employees eventually stop doing much hoping they remain under the radar.
The end result of electing people who aren't good decision makers is that it destroys the community. The public, who never attends meetings to witness this behavior, can never figure out why their community continues to degrade and why their children immediately move away when they become adults. For the community to succeed you really do need a balance.