The Paranoid Style in American Politics the title and you’ll get a number of responses for this article. I found the reference in a recent Paul Krugram article on a similar subject.

Some choice excerpts from the original 1964 paper;

But the modern right wing, as Daniel Bell has put it, feels dispossessed: America has been largely taken away from them and their kind, though they are determined to try to repossess it and to prevent the final destructive act of subversion. The old American virtues have already been eaten away by cosmopolitans and intellectuals; the old competitive capitalism has been gradually undermined by socialistic and communistic schemers; the old national security and independence have been destroyed by treasonous plots, having as their most powerful agents not merely outsiders and foreigners as of old but major statesmen who are at the very centers of American power. Their predecessors had discovered conspiracies; the modern radical right finds conspiracy to be betrayal from on high.

another good one;

Finally, the country is infused with a network of Communist agents, just as in the old days it was infiltrated by Jesuit agents, so that the whole apparatus of education, religion, the press, and the mass media is engaged in a common effort to paralyze the resistance of loyal Americans.