Experts: Trump's Muslim ban would cripple the immigration system

Currently, the U.S. immigration system costs over $21.5 billion per year, counting spending by Homeland Security and the State Department.

Experts said actually implementing a global screening test for Muslim immigrants could swell that cost to $40 billion, $60 billion, or far more.

“It would be uncountable,” said Philip French, a 30-year veteran of the Foreign Service.

Even if Congress granted that new funding, budget experts say it would be hard for the government to grow at that scale.

“It’s hard to do — there’s no entity that can double or triple its scale overnight easily,” said Douglas Holtz-Eakin, a former Director of the Congressional Budget Office and aide to John McCain.

“If it’s done too quickly,” he warned, “a lot of the money will be wasted.”