When (and why) did the US start calling its citizens consumers?

Voters fill out their ballots in the patriotic voting booths at Merrill Auditorium / Check out counters in Walmart. Brianna Soukup/Portland Press Herald via Getty Images / Jeffrey Greenberg/UIG via Getty Images

Today, the terms "citizen" and "consumer" are often used interchangeably by authors, journalists and politicians. To some experts, this shift has disturbing implications. But how important is a word? How did this switch occur, and why?