The problem with looking only at people who are vocal online, is that you only see things from a small bubble of people, and only the things, that don't get downvoted/removed by moderators.
If you looked at e.g. reddits users and their comments, Bernie Sanders would be on his way to a second term.
Since the article is mentioning ICE, and i'm from a small eu country, really close to relatively shitty non-eu countries, I know that what people say or don't say online is different from what people think in their heads. Being a developer here, and trying to find work in USA is a big pain in the ass... if you're a good developer, but without a formal education, might be even impossible. Even if you have everything, have a good resume, big projects, get invited by facebook/google/whoever, going through the endless stream of bureaucracy takes a lot of time and a lot of money (which is understandable, because hiring local is good for local workers, and importing foreign workforce means lowering pay, due to more supply). When such people get their papers, green cards, and work in USA for some time, their opinion on illegal immigrants, who skip the whole process (and sometimes even get praised for that) is a lot different than the comments you see on reddit. They might not say it there, but they say it here.