Unless mass views have some place in the shaping of policy, all the talk about democracy is nonsense.V.O. Key (1961, 7)
Popular control of public policy is a central tenet of democratic theory. Indeed, we often gauge the quality of democratic government by the responsiveness of public policymakers to the preferences of the mass public as well as by formal opportunities for, and the practice of, mass participation in political life. The potential mechanisms of democratic popular control can be stated briefly. In elections, citizens have the opportunity to choose from leaders who offer differing futures for government action. Once elected, political leaders have incentives to be responsive to public preferences. Elected politicians who offer policies that prove unpopular or unpleasant in their consequences can be replaced at the next election by other politicians who offer something different.
Of course, this picture describes only the democratic ideal. A cynic would describe the electoral process quite differently: Election campaigns sell candidates in a manner that allows little intrusion by serious issues. Once in office, winning candidates often ignore whatever issue positions they had espoused. Voters, who seem to expect little from their politicians, pay little attention anyway.
The actual performance of any electoral democracy probably falls between these extremes. Acknowledging the factors that impede effective democratic representation, we can ask to what degree does public opinion manage to influence government decisions? This is an empirical question, often noted as the central question of public opinion research (Key, 1961; Converse, 1975; Burstein, 1981; Kinder, 1983; Erikson, Luttbeg, and Tedin, 1991).