President Trump's move Friday to suspend refugee entry into the U.S. and restrict entry from Muslim states is flatly illegal, a top immigration policy analyst writes.

David J. Bier, an immigration analyst at the Cato Institute’s Center for Global Liberty and Prosperity, said in a New York Times Op-Ed on Friday that Trump's Friday executive order is illegal.

"The order is illegal," Bier wrote. "More than 50 years ago, Congress outlawed such discrimination against immigrants based on national origin.

"Nonetheless, Mr. Trump asserts that he still has the power to discriminate, pointing to a 1952 law that allows the president the ability to 'suspend the entry' of 'any class of aliens' that he finds are detrimental to the interest of the United States," he continued.


"But the president ignores the fact that Congress then restricted this power in 1965, stating plainly that no person could be 'discriminated against in the issuance of an immigrant visa because of the person’s race, sex, nationality, place of birth or place of residence.'"

Trump on Friday signed an executive order that he said would provide a thorough vetting of refugees to ensure that "radical Islamic terrorists" cannot get into the United States.

Trump's order indefinitely blocks refugees from war-torn Syria from entering the U.S. and suspends all refugee admissions for 120 days while the administration determines which countries pose the least risk. 

Admission will resume only after vetting has been deemed "adequate" by the secretary of State, the secretary of Homeland Security and Director of National Intelligence.

Bier's full piece on Trump's ban can be read at The New York Times.