The whole argument is political correctness gone to the level of emotional coddling.
Look! It’s this simple:
If I drive a vehicle and if I do not have insurance or a drivers license, I am still a “driver”. However, I am an undocumented driver and am not driving legally. If I am not driving legally, then I am driving illegally. I am an illegal driver.
It doesn’t matter whether I’m a nice person or not, or whether I work, have children, or am a genius. If I hit your car and damage it, no matter how nice I am, you will find my illegal status problematic.
If I immigrate to this country and reside here, and if I do not have the appropriate visa or whatever papers I need, I am still a resident–I am still an immigrant. However, I am an undocumented immigrant and did not immigrate here legally. If I did not immigrate legally, then I am an illegal immigrant.
For those who don’t like the word “illegal”, you should understand that it means that something is not within the scope of what the law allows or prescribes. More simply, not in accordance with applicable laws.
We can try to make those who are here illegally feel less outside the law by simply calling them undocumented, but that does not change the law. And we can try to make ourselves look more progressive, compassionate, and accepting. But stupidly arguing that black is not black, and that white is not white–well, it makes the person look plain stupid.