Paranoid Styles

"A contributor to the Hartford Courant declared that President Thomas Jefferson is 'the real Jacobin, the child of modern illumination, the foe of man, and the enemy of his country.'
"In the 1820s and ’30s, apprehensions about what the Masons were getting up to in their secret Lodge meetings fueled a national political movement. Former President John Quincy Adams (who had been defeated by the Mason Andrew Jackson) ran for governor of Massachusetts on the Anti-Masonic ticket in 1834. In his book 'Letters on Freemasonry,' he wrote that Masonry 'is wrong—essentially wrong—a seed of evil, which can never produce any good.' If the Illuminati had been feared for their irreligion, the Masons were condemned not just as freethinkers, but as occultists, Jesuits and even Jews of a sort. The anti-Masonic panic was followed in short order by the know-nothing era of anti-Catholic Nativism.
"And of course there is race."

Arthur Godwag in Salon connects past conspiracy theories to today's politics.