Ben Bova says this about The Marching Morons:
The most prescient — and chilling — of all the science fiction stories ever written, though, is “The Marching Morons,” by Cyril M. Kornbluth, first published in 1951. It should be required reading in every school on Earth.
PZ takes the storyline of The Marching Morons to task and throughly deconstructs it’s premise. I recommend you read his post.
I would suggest to Mr. Bova that the most prescient — and chilling — of all the science fiction stories ever written is actually If This Goes On by Robert Heinlein, first published in 1940.
In If This Goes On, we are introduced to a United States that has become a (corrupt) Theocracy. Nehemiah Scudder, a backwoods (fundamentalist) preacher, was elected President. He is the last President elected as he appoints himself as the “Prophet” of the United States.
The story is about a rebellion to overthrow the theocracy.
The reason that I believe it to be one of the scariest SF stories ever written is that I feel that the United States is not far from becoming a Theocracy. And the President is doing his damnest to grab all the power he can, and the next step would be dictatorship.
More information on the story If This Goes On.
More information on the President’s grab for more and more powers.