what if we just put them all on an island and then blew it up immediately

POC? Proof of Concept?

Yes but look at the alternative: a country united under far right rule. We suffered for 4 years of that and are looking at another 4 years of it if the dumbass anti-Biden memes are taken seriously by enough sheeple.

But there's millions of them.

Even if we don't tolerate them, what should we do with them?

He's not talking in good faith. I'm married to a first-gen immigrant from Mexico. I can tell you how "they" move. Unless they're rich out the gate, in which case there's a completely different process, they save up money for years, ask for money from relatives, live in extreme discomfort, and then eventually are able to move.

Once established, it's not like "they" can pick up at any time and relocate. Now they're trapped in three or four jobs working the entire day, with still barely enough money for rent and food.

Eventually, some of "them" might be fortunate enough to be able to afford the massive investment of time and money for residency and maybe even citizenship.

Maybe even some of "them" will fall in love and get married and start a beautiful life together.

But maybe "they" and even their spouse have misfortune. Healthcare can totally collapse you. Maybe "they" and their spouse save up money for years, but it's never enough. "They" have got PTSD from their prior life experiences, and their spouse develops health problems. Neither of them want these things to happen, but one ends up in and out of psych wards and psychiatrists' offices, and the other ends up shitting himself for more than five years, finally after thousands and thousands of dollars discovers he has celiac, but has also fucked other things up in the meantime by developing addiction to alcohol and opiods, which are so easy to become addicted to in this society. So their big plans to move to the big city keep falling through. "They" might lie awake at night feeling tremendous guilt about this, on top of everything else, even though it's not "their" fault.

That's how "they" move, and that's how many of "them" might not be able to just fucking relocate like some privileged neckbeard from lemmy.world suggests.

I know many other immigrants and refugees. I know many similar cases.

TL;DR "They" are the same as "us"

Yes. One is more uncomfortable than the other. I believe you already understand that.

They move at least once in order to be immigrants, from their home country to the foreign country they now live in.

I mean literally every single immigrant because that's the definition of an immigrant.