The US public discourse is so dehumanized today that anyone who is not "with them" is literally not a human anymore. Even within the country itself "the leftards" are considered an obstacle which can be removed if only enough force is applied.

Sending armed agents at protesters is seen as being the same thing as sending pest control to clear out beaver dams on the creek. Nobody cares what the beavers think, they are not human, they do not have feelings. They are simply a menace to be dealth with.