Is the role of a government to do the will of the people, or to do whats right for the country?

Im reflecting from the pov of a parents role re: the kids. If you give the kids what they want, its going to be soda and candy every day of their lives. Some deciaions are tough, e.g. delayed gratification, and holding ones ground, but do voters even care about stuff like that?

Can we even hope on common sense, when the population is concerned?