THE PARANOID STYLE IN AMERICAN POLITICS by Richard Hofstadter. 315 pages. Knopf. $5.95.
The Great Conspiracy Against America first came to light in 1797, when the pulpits of New England rang with denunciations of the Illuminati, a sinister society of freethinkers who were purportedly prepared to attack the U.S. with a number of secret weapons—among them a tea that caused abortion and a "method for filling a bedchamber with pestilential vapours." By 1835, control of the conspiracy had passed to the Pope, whose Jesuits were reported "prowling about all parts of the...