It's grand to say the law should reflect the "will of the people", but how to discover what the will of the people is?

From the articles here in Slate, and other outlets with agendas of both the left and the right, I('d say the will of the people is only listened to when it is in sync with the will of the congress. Otherwise, the people are referred to as dumb, misguided, lazy, fat, ignorant, crazy...you get the picture.