The question that this word raises concerns the obligations of persons chosen to represent the citizens whose votes send them to represent to the legislature of a constitutional government, whether it be an oligarchy with limited suffrage or a democracy with universal suffrage.
When questions come before the legislative body of which they are members, should their response be determined by the view held by their constituents, or should they decide which side to take on an issue before the legislature in terms of their own judgment of what is the right solution of the problem, whether or not it concurs with view held by their constituents?
Edmund Burke answered this question in his Letter to the Sheriffs of Bristol, whose representative he was. He said that if they had elected him because of his intellectual qualities, they should look upon him as better able than they do decide which side of the issue being debated in the legislature was the correct side to take. He did not regard himself as an envoy to act as instructed by them.
Today, most of our legislators are very attentive to opinion polls, as well as to the letters they receive from their constituents. If they are guided by these indications, they do not regard themselves as functioning in the way that Burke recommended.
Some comprise between these two position is possible. It is sometimes thought that the phrase "government by the people" call for participatory rather than representative democracy. But if the state or nation is large and population, it is not feasible to conduct its affairs in the manner of a small-town meeting in which the citizens take a direct and active part in their own government. On the other hand, their wishes should not be despised. (I recommend to readers that they consult J. S. Mill's Representative Government. They will find in Chapter 12, which is entitled "Ought Pledges to Be Required from Members of Parliament," Mill's views on the question dealt with by Edmond Burke).