Even if this is true, President Trump and the GOP are carefully constructing a narrative which will temper people's natural compassion with a fear of brown people pouring across an open Southern border and destroying America.
All Hispanics are members of MS-13 (or at least potential members) and should be both reviled and feared.
Again, y'all overestimate. These are the same folks that have spent years explaining that it's fine for police to drive up and beat/kill black and brown kids that are just walking around or sitting in a park somewhere. They're the same ones who celebrated when cops pull out military gear to lay siege to nonwhite neighborhoods.
It's not anything Trump, or they, carefully constructed. In fact, it's the same crass white supremacy that we've been seeing at the forefront of GOP politics for at least the past decade - and on am radio and the like for far longer than that, no different than than Hazel Bryan screaming at the Little Rock 9. The idea of a nonwhite person who isn't dangerous to them, of a black guy who is legitimately smart and president, is simply not in keeping with what little they know. It's not that they're thoughtful, but rathe that they're clueless - and that's quite enough to motivate them to plow their car into a crowd, or to shoot up a black church. Certainly, this recording of weeping children will do nothing. The sadism, fear, and hatred are first, the "logic" is mere rationalization - thus the constant, slapdash "justifications" and lies.
At most, it's possible that Stephen Miller is calculating about it, but the truth is that it's the old-fashioned white supremacists Dolt 45 and Jeff Sessions in charge of this. And in truth, this one's on white people to fix, since it's your relatives and "friends" that voted for this pack of ethnostate lovers and white supremacists - I have coworkers who did, but absolutely no friends of family that did so.
And if you did vote for him - my only use for you is an a sounding board. You need an intervention in real life, not from behind a computer screen.