As far as Syrian refugees, and I posted this before, they already have "extreme vetting". I think it's easier for Trump supporters to digest, they're coming to kill us all. Doesn't requiring thinking. Here it is again:
http://www.politifact.com/truth-o-m...donald-trump-says-theres-no-system-vet-refug/
"The vetting begins with the United Nations High Commissioner for Refugee, which determines who counts as a refugee, who should be resettled (about 1 percent) and which countries would take them. This alone can take four to 10 months.
If the UNHCR refers refugees to the United States, they then face scrutiny from federal intelligence and security agencies.
Their names, biographical information and fingerprints are run through federal terrorism and criminal databases. Meanwhile, the refugees are interviewed by Department of Homeland Security officials. If approved, they then undergo a medical screening, a match with sponsor agencies, "cultural orientation" classes and one final security clearance.
Syrian refugees in particular must clear one additional hurdle. Their documents are placed under extra scrutiny and cross-referenced with classified and unclassified information.
The process typically takes one to two years or longer and happens before a refuge ever steps onto American soil. Ultimately, says the State Department, about half are approved, and thereโs no real precedent of a terrorist slipping in through the vetting system."
So about 3 years.
"Given how easy it is to send a European extremist to the U.S. via Europe,
why would an ISIS guy in Syria wait the three years it takes to get refugee status?" Speckhard said."