President Donald Trump’s moves to roll back Temporary Protected Status and other humanitarian programs for immigrants are pushing hundreds of thousands of previously legal foreigners into a shadow workforce, with Thursday’s Supreme Court ruling set to accelerate the shift.

The court’s justices gave the Trump administration the green light to strip protections from more than 350,000 people from Haiti and Syria. Even before that, some 600,000 working adults had already lost the right to live and work in the US since last year as the White House sought to end programs for migrants from places including Venezuela, Cuba and Afghanistan, according to the pro-immigration advocacy group FWD.us. At the end of March, it estimated 3 million immigrants in the labor force could face the same fate. Some have been in the US for decades.