One thing that Trump did very effectively was take advantage of how people will selectively hear what they want to hear if they're desperate, and not pay attent

One thing that Trump did very effectively was take advantage of how people will selectively hear what they want to hear if they're desperate, and not pay attention to fine details that might suggest a different meaning than they're taking. For example, someone who thinks that doing a lot of labor is a sign of good moral character might think "deport the lazy criminals" sounds reasonable, and ignore the details which suggest that the crime in their mind is "being foreign", leading to surprise when those you thought of as "good people" are being deported. (None of that removes the responsibility for the consequences of your actions, of course, just that it's not necessarily that they thought he wouldn't follow through, and more that they only remembered what they wanted to hear.)