“Having a vote once every four years is not the same thing as democracy.”

Unknown year

Green Party presidential candidacy speech (2000)

1990s, The Decline and Fall of the American Empire (1992)
Context: Every four years the naive half who vote are encouraged to believe that if we can elect a really nice man or woman President everything will be all right. But it won't be. Any individual who is able to raise $25 million to be considered presidential is not going to be much use to the people at large. He will represent oil, or aerospace, or banking, or whatever moneyed entities are paying for him. Certainly he will never represent the people of the country, and they know it. Hence, the sense of despair throughout the land as incomes fall, businesses fail and there is no redress.

via tweet https://twitter.com/IvankaTrump/status/1324720284948193285 On November 6, 2020
2020

The consumers are the sovereign people. The capitalists, the entrepreneurs, and the farmers are the people’s mandatories. If they do not obey, if they fail to produce, at the lowest possible cost, what the consumers are asking for, they lose their office. Their task is service to the consumer. Profit and loss are the instruments by means of which the consumers keep a tight rein on all business activities.
Source: Bureaucracy (1944), Chapter I: Profit Management, § 1: The Operation of The Market Mechanism

Interviewed by Jon Stewart on The Daily Show http://www.thedailyshow.com/video/index.jhtml?videoId=18090&title=kurt-vonnegut/ (13 September 2005)
Various interviews

1970s, Fear and Loathing: On the Campaign Trail '72 (1973)
Context: We've come to a point where every four years this national fever rises up — this hunger for the Saviour, the White Knight, the Man on Horseback — and whoever wins becomes so immensely powerful, like Nixon is now, that when you vote for President today you're talking about giving a man dictatorial power for four years. I think it might be better to have the President sort of like the King of England — or the Queen — and have the real business of the presidency conducted by... a City Manager-type, a Prime Minister, somebody who's directly answerable to Congress, rather than a person who moves all his friends into the White House and does whatever he wants for four years. The whole framework of the presidency is getting out of hand. It's come to the point where you almost can't run unless you can cause people to salivate and whip each other with big sticks. You almost have to be a rock star to get the kind of fever you need to survive in American politics.

Widely attributed to Franklin on the Internet, sometimes without the second sentence. It is not found in any of his known writings, and the word "lunch" is not known to have appeared anywhere in English literature until the 1820s, decades after his death. The phrasing itself has a very modern tone and the second sentence especially might not even be as old as the internet. Some of these observations are made in response to a query at Google Answers. http://answers.google.com/answers/threadview?id=389308
The earliest known similar statements are:
A democracy is two wolves and a lamb voting on what to have for lunch.
Gary Strand, Usenet group sci.environment, 23 April 1990. http://groups.google.com/group/sci.environment/msg/057b1c6389f4776f?dmode=source
Democracy is not freedom. Democracy is two wolves and a lamb voting on what to eat for lunch. Freedom comes from the recognition of certain rights which may not be taken, not even by a 99% vote.
Marvin Simkin, "Individual Rights", Los Angeles Times, 12 January 1992. http://articles.latimes.com/1992-01-12/local/me-358_1_jail-tax-individual-rights-san-diego
Democracy must be something more than two wolves and a sheep voting on what to have for dinner.
James Bovard, Lost Rights: The Destruction of American Liberty (1994), ISBN 0312123337, p. 333.
Also cited as by Bovard in the Sacramento Bee (1994) http://www.giraffe.com/gr_wolves.html
Misattributed
Variant: Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote.