How something is said can completely change the meaning.
When Trump said, "And some, I assume, are good people.", he is being sarcastic and what he means is the very opposite. What he means is they are all bad people. He knows it's not true and most everyone else does but he uses it to stir the pot and elevate the rhetoric from contempt to hate.
I got no sarcasm from him on that.
I suppose you have hear him say it. In the speech, he pause and then offhandedly says, " And some, I
assume, are good people." His use of the word assume conveys the idea that he's not sure any of them are good people. He just doesn't know if there are any good Mexicans.
Sounded to me, like it occurred to him, while he was correctly discussing the dangers of millions and millions of completely unvetted people crossing the border, that he wanted to cover his ass, so libs couldn't spin it as a "racist" statement.
This was in a campaign speech in Aug 2016. He actually delivered the same idea over and over. Some times Mexican are rapist and sometimes they are murders and rapist. He keeps invoking the centuries-old myth that men of color are sexual predators. Thus Mexicans are always rapist and sometimes also murders but always rapist.
Nothing just occurs to Trump in his campaign speeches. Although his speeches may sound extemporaneous, they certainly are not. He knows exactly what he is going to say and how he's going to say it. Every hear him speaking off the cuff or go off script. Here he is explaining the Nuclear Deal in 2015.
"Look, having nuclear — my uncle was a great professor and scientist and engineer, Dr. John Trump at MIT; good genes, very good genes, okay, very smart, the Wharton School of Finance, very good, very smart — you know, if you’re a conservative Republican, if I were a liberal, if, like, okay, if I ran as a liberal Democrat, they would say I'm one of the smartest people anywhere in the world — it’s true! — but when you're a conservative Republican they try — oh, do they do a number — that’s why I always start off:
Went to Wharton, was a good student, went there, went there, did this, built a fortune — you know I have to give my like credentials all the time, because we’re a little disadvantaged — but you look at the nuclear deal, the thing that really bothers me — it would have been so easy, and it’s not as important as these lives are (nuclear is powerful; my uncle explained that to me many, many years ago, the power and that was 35 years ago; he would explain the power of what's going to happen and he was right — who would have thought?), but when you look at what's going on with the four prisoners — now it used to be three, now it’s four — but when it was three and even now, I would have said it's all in the messenger; fellas, and it is fellas because, you know, they don't, they haven’t figured that the women are smarter right now than the men, so, you know, it’s gonna take them about another 150 years — but the Persians are great negotiators, the Iranians are great negotiators, so, and they, they just killed, they just killed us"
He wanders all over the place, repeats himself, goes off subject and is often incoherent." Compare that to a campaign rally. Huge difference.