Immigrant doctors are vital to U.S. healthcare, making up 25% of all physicians and key to addressing a growing doctor shortage across the country.

The immigration policy allows some children of immigrants brought to the U.S. to receive a renewable, two-year period of deferred action from deportation and be eligible for a work permit.

As Stephen Miller, Trump’s chief of staff, wryly observed, such protests could boost the president’s approval rating past 60%.For years, immigration rules have simply not been enforced.