In the aftermath of the terrorism in Paris, Syrian refugees are denied entry by many of the US states. Many of these states are governed by racists and bigots. Many of them found the Paris tragedy as a sufficient justification to object to the entry of these unfortunate refugees from war torn countries to whom the incidents like Paris had been a regular feature.
The Jews of Europe faced similar problems in the 1930s and 1940s. Here is a link to an article on fleeing Jews from Europe in the 1930s.