Yes, mainly by groups that actually WERE a threat to national security in some form or another, the KKK, the American Protective Association, the Know-Nothings... during the late 1800s early 1900s there was a lot of that sort of thing.
The standard position was that Catholics would overwhelm the native Protestant electorate, vote for Catholics loyal to the Pope and then turn the whole place over to Rome.
An example from the APA: "The Roman Catholic attack on our public-school system. The attempted foreignizing, by force of whole communities, in language and religion, by Romish priests. The complete control of our great cities by Romanism. The fact that our army and navy are almost wholly Romanized. The remarkable increase of untaxed church property. The frequent desecration of the American flag by priests. The Jesuit control of the heads of government at Washington. The well-known public declaration of the Pope that the United States is his one bright hope for the future." (from the New Encyclopedia of Social Reform, Funk and Wagnalls 1908)
Worth taking seriously? Obviously not, but still some of it seems very familiar. How do we say "this time we really mean it"? Because yes, this time the threat is real.
Firts off let me say I’m no longer a practising RC but still find myself defending the Roman Catholic Church, albeit reluctantly. The reason is at the end of this post.
Roman Catholics are distrusted for historical reasons stretching back centuries in Europe. But there was a military incident in the Mexican-American War that severely complicated the issue for U.S.citizens who were Catholic.
During a battle in that war the Mexicans were losing. They appealed to Irish immigrant U.S. soldiers/cavalrymen that their Roman Catholicism made them more akin to Mexicans than to the Protestants in power in the U.S.A. The Irish went over to the Mexican forces and the remaining American force was slaughtered.
To say this poorly affected the reputation of Irish immigrants in the U.S.A. is an understatement.
As to Catholicism being a threat to national security in the present, well, take a look at how the RC heiracrchy is behaving about the invasion of the U.S. by Mexican illegals. Their stance is disgraceful, and violates the division between church and state.
Standing up for protecting the unborn from murder has my support as life is a right from God.
Interfereing in the sovereign right of a nation’s people to collectively determine immigration policy does not have my support. The RC church heirarchy is trespassing dangerously outside their hallowed responsibilities.