Hey, it's just another FUD* policy ordered up by our wannabe Emperor. It's also worth noting that Harvard has been cautioning its foreign-born scholarship students NOT to leave the US for any reason, lest they be denied re-entry.
But WAIT! There's one even better, just reported today (27 Aug): furriner children here in TrumpLand who were granted LEGAL 'deferred action' status to receive treatment for life-threatening health conditions (typically not available to them in their home country) are now receiving Immigration Agency letters ordering them out of the country within 33 days -- or else! His Orange Self has spitefully cancelled a long standing humanitarian policy that's been in force for years.
So... or else, what? Defy the order, stay here, get incarcerated and [hopefully] receive medical treatment while in Alien Prison? Or obey and leave, and die for certain. Maybe the Immigration officers will organize a flying squad to raid the hospitals, unplug wires and tubes and hustle them sick kids onto the next flight leaving the country?
In Oz the scarecrow had no brain; the cowardly lion had no courage; and the tin woodman had no heart. Here in 'merica, if taken all together, they'd make a Trump!
So how do we explain the heartless, brainless, and cowardly sycophants who enforce his policies?
*FUD: fuckin' ugly discrimination