Between classes, when throngs of students stream into and out of Columbia University ’s campus, the security lines can back up like a TSA checkpoint. There’s a switch-back path of metal fencing that leads into a white tent, where two sets of guards check and then swipe campus ID cards before letting students in and out.

According to the sources, it was part of the Trump administration’s crackdown on individuals it has described as espousing the views of Hamas.

Leqaa Kordia, a Palestinian from the West Bank, was arrested by immigration officers for overstaying her student visa, the Department of Homeland Security said.