The people who think illegal immigrants shouldn't be illegal don't think anyone should be illegal. What's the double standard? It's not like they think black people should be allowed in but white people shouldn't.
What's hard to grasp is how you think this applies to a discussion about differing facts based on political leaning. Nobody disagrees with the facts here, only on what should be done going forward. So, not really relevant to the discussion.
This isn’t hard to grasp.