Common practice is that an elected official is elected by the voter and the voter expects their elected officials to listen to what all voters are saying. Both McCain and Obama have repeatedly stated that if elected, they will listen while representing the ordinary person. (Think,Joe, the plumber). Candidates should campaign to represent ALL the people, those considered "ordinary" people, poor, wealthy, privileged, intellects, those with disabilities, etc., and all without prejudice of race or belief.
Any politician who does not listen to the opinion of the electorate, defaults on their campaign claims of inclusive listening and learning. listening even to those who may have voted against them. To do otherwise is a betrayal of the public trust.
However, overlooked in the process is that elected officials are elected by voters to make the best decisions based on the knowledge that qualified them as viable candidates, on the elected access to research resources, the assistance of their peers from both parties, the input of career bureaucrats, staff and lobbyists, career diplomats, experts in various fields foreign to the elected sphere of knowledge, special interests, etc. The resulting knowledge available to the elected is mostly unavailable to the average voter. This furthering of the elected education, sorting out facts presented by all should lead them to determine what is best for ALL. Their actions should be in the best overall interests to the stability and well-being of their constituents, community, city, county, state and country.
The elected must not be "beholden" to any minority special interest group and to those who raise disportionate amounts of money for their campaigns.
It is a betrayal to those who put them in office if they sacrifice their learned judgment to what may or may not be a populist majority.
Majorities are not always right. For doubters, remember that the majority in America believed in slavery for centuries. Some elements in "not so free" nations in the world still do.