It may be hard today for Americans to believe, but there was a time when U.S. presidents recognized that our immigration laws were designed to protect the American people from criminals and agents of enemy nations. Roosevelt, Eisenhower, Kennedy and their predecessors aggressively enforced those laws, denying entry to agents of enemies such as Nazi Germany and Communist dictatorships.

Essential to enforcement was the careful screening of every would-be immigrant from an enemy nation in order to separate the legitimate ones from those who posed dangerous political or criminal threats.

Jacques Gadiel’s experience as a refugee immigrant showed the thoroughness that President Franklin Roosevelt’s administration employed to safeguard our people.

Gadiel was my father, a German Jew, a perfect target for murder by Hitler's government. In addition, he and my mother, a German Protestant, had committed the ultimate “crime” of marrying in violation of the Nazi race laws. As prime targets for the Gestapo, they agreed that if they were somehow separated, each would try to reach safe haven in any country that would accept them.

As a result, with a visa issued by the U.S. chargé in Lisbon, Portugal, my father arrived alone in the United States on April 25, 1941. His German passport had a big red "J" for "Juden" (Jew) stamped on it. He was in proximate danger of being murdered, as legitimate a refugee as one could be. Despite that legitimacy, the FBI took him into custody as soon as he arrived. He was held for over a week, during which time federal agents including a German-born psychiatrist carefully interrogated him to ensure that he was, in fact, a legitimate refugee and not a threat to U.S. security.

"They practically looked under my fillings to make sure that I was what I said I was," he told me years later. I asked him if he had been angry or offended that the U.S. government treated him in this manner after he had evaded the Nazis. His response: "No. Not at all. I was glad. I didn't want Nazis in this country any more than FDR did. I came here to be safe."

And for the rest of his life, he was. But not so his grandson – my son, James Gadiel, who was murdered at the age of 23 by Islamic terrorists as he worked in the World Trade Center on Sept. 11, 2001.

James died because the screening of immigrants has been abandoned.

That abandonment was begun by Pres. Carter. In 1980 he accepted 125,000 Cuban refugees with no inspection whatever. Fidel Castro exploited Carter's negligence by emptying his prisons of criminals and shipping them to us among the legitimate refugees.

Later, Pres. Reagan signed an amnesty which was exploited by criminals and illegal aliens using forged documents to remain in the USA and obtain citizenship. Illegal immigration (that is, immigration without screening) continued under George H.W. Bush, and Bill Clinton permitted, even encouraged, ever more massive illegal immigration.

It was during his administration that the 9/11 terrorists were admitted into the U.S. Even after the 9/11 attacks President George W. Bush continued to refuse to enforce our immigration laws leaving our borders wide open to Islamic terrorists and other criminals.

That reckless – even criminal – policy has been brought to its ultimate by President Obama who now imports, by the hundreds of thousands, people from nations whose cultures and governing entities are enemies of our values, religions and freedoms – all without screening.

From FDR's policies designed to protect our people to Obama's policies of intentionally bringing in the enemy. What a sad descent from decency and sanity.

Peter Gadiel is a retired businessman and lawyer. For 10 years after the murder of his son he led 9/11 Families for a Secure America, consisting of families and victims of the September 11, 2001, terror attacks and other violent crimes committed by illegal aliens.