OK, OK, we are generally pro-immigration here. And though no “person” can be illegal per se, one can do things that are illegal and as such the rule of law exists to address these issues. We do have a country, with borders correct? This is something that most people, even many libertarians think is a legitimate role for government, correct?
What we see here is the real (electoral) reason there is the effort to keep borders as open as possible.