Harvard and the federal government are locked in a battle that boils down to turning over records on international students. But Harvard says it is also about the First Amendment.

On Thursday, the Department of Homeland Security had abruptly revoked the university’s ability to enroll foreign students.

Harvard University is challenging the Trump administration's decision to bar the Ivy League school from enrolling foreign students, calling it unconstitutional retaliation for defying the White House's political demands. It is the school's second suit against the Trump administration.