With the ongoing crisis creating refugees in the middle east there is a vocal portion of the population urging governments not to accept these refugees as some of them may be terrorists in disguise or otherwise dangerous.
Did the waves of refugees to reach North America in the 20th century inspire the same fears and concerns.? Were Hungarians, Czechs, and Vietnamese fleeing communism in their home countries commonly characterized as being possible spies or fifth columnists?
Yes. The Emergency Quota Act of 1921 and the Immigration Act of 1924 were both driven by concerns about the enormous number of immigrants generated by what we might now call refugee outflows in the aftermath of the First World War and the national revolutionary period that followed in many countries.
The debates and hearings over what would become the Lodge-Fish Resolution in 1922, which gave US support for the Balfour Declaration promising the creation of a "national home for the Jewish people" in Palestine were in sizable part a recognition on the part of American Zionists and American lawmakers that a homeland for the Jews in Palestine would be an alternative to mass Jewish immigration to the United States, which would shortly be cut off.