While I don’t disagree with the point that they are afraid of the losers coming home, I think they are absolutely terrified of the successful Mexicans coming back.
It’s the successful ones who have the drive to overturn the political system. They’ve not only seen something more successful, they’ve actually lived and thrived using our system, and they aren’t going to settle so easily.
It takes both to make a revolution. Both the successful ones with the drive, and the not-so-successful millions of men of military age who will actually make it happen.