In an interview with Fox News host Sean Hannity last night, Ted Cruz defended his proposal to block Syrian Muslim refugees from entering the U.S. by insisting that Muslims are allowed “to lie to carry out jihad,” and therefore, we’ll never really know which Muslims don’t support violent extremism.

Cruz added that when Sen. Patrick Leahy, D-Vt., cited his Irish and Italian ancestors as reasons to oppose restrictive immigration policies, “I responded to Pat Leahy and I said, ‘You know what, on my mother’s side, my ancestors were Irish and Italian. The difference was, they weren’t coming here to blow up and murder innocent civilians.’”

Cruz may be interested to know that Nativists in the era of high Irish and Italian immigration considered such migrants to be violent threats.

The infamous Palmer Raids, sparked in part by a series of bombings carried out by Italian anarchists, were based on a fear that southern Italian immigrants presented an internal threat to the U.S. As author George De Stefano writes, many politicians at the time had concluded that “America was under attack by dangerous foreign radicals” and restrictive immigration laws were needed “to protect the nation from southern and eastern European immigrants, who purportedly would infect America with their dangerous radical ideas and engage in violent subversion.” Italian migrants were also seen as “unassimilable,” “dangerously radical” and “prone to violent criminality.” Decades before the Palmer Raids, Italian immigrants “were even accused of a conspiracy to inundate the United States with Italian fleas.”

Author Anthony V. Ricco detailed how the Palmer Raids specifically targeted Italians: “Armed agents stormed homes of Italian immigrants without warning, prisoners were detained without counsel, and innocent Italians were deported to Italy. In West Virginia, Colorado, and Louisiana, Italians were lynched by angry mobs of vigilantes.”

Irish newcomers were also treated as violent menaces, as Peter Behrens noted in the New York Times:

It’s embarrassing to listen to prosperous 21st-century Americans with Irish surnames lavish on Mexican or Central American immigrants the same slurs — “dark,” “dirty,” “violent,” “ignorant” — once slapped on our own, possibly shoeless, forebears. The Irish were seen as unclean, immoral and dangerously in thrall to a bizarre religion. They were said to be peculiarly prone to violence. As caricatured by illustrators like Thomas Nast in magazines like Harper’s Weekly, “Paddy Irishman,” low of brow and massive of jaw, was more ape than human, fists trailing on the ground when they weren’t cocked and ready for brawling.

An entire political movement, the American Party, also known as the Know Nothings, was founded in response to fears that Irish migrants were “a dangerous threat to the ‘nature’ of Protestant America, and thus to America itself” and should be prohibited from having certain rights since they “owed their allegiance, not to the burgeoning American government, but to the Pope, whose autocratic ruling style was antithetical to American democratic values.”

But we won’t hold our breath: Cruz didn’t seem to learn a thing from the last history lesson we gave him.