Doubling down on his proposal to create a national registry system for all Muslims, Republican presidential candidate Donald J. Trump called Monday for a "total and complete shutdown" of Muslim immigration to the U.S.

Trump released his call to action in a statement just hours after the news broke that the two shooters involved in last week's San Bernardino massacre had pledged allegiance to the Islamic State, often referred to as ISIS or ISIL.

He cites a poll released last summer that showed Muslims' "ominous levels of support" for jihadist terrorism, as well as the basic Islamic legal system known as sharia law. But the poll, conducted by the Center for Security Policy, came under fire immediate. A team from Georgetown University argued that the poll should not be taken seriously, as it comes from "an organization with a history of producing dubious claims and 'studies' about the threat of shariah, and was administered using an unreliable methodology."

Still, the business mogul argues we don't even need the data to support his proposal after all.

"Without looking at the various polling data, it is obvious to anybody the hatred is beyond comprehension," he said in the statement. "Where this hatred comes from and why we will have to determine. Until we are able to determine and understand this problem and the dangerous threat it poses, our country cannot be the victims of horrendous attacks by people that believe only in Jihad, and have no sense of reason or respect for human life. If I win the election for President, we are going to Make America Great Again."

You can read the full statement here.