>If you do believe that there are violent criminals coming through the porous border, whether it's 1% of the illegal immigrants or 100% of them, trying to seal the border off is not irrational.

Yes it is. Building a 1900 mile long wall with moats and barbed wire and armed guards ordered to shoot on sight across an entire continent because a fraction of illegal immigrants might be violent criminals is the definition of irrational.

Particularly when the same could be said of the border with Canada but no one is concerned about that at all.

> I'm not endorsing the physical wall itself, as I know a ton of illegal migrants are just overstaying visas, and I've heard of ladders and tunnels.

But Trump was talking about a physical wall. And a physical wall is what Trump supporters voted for.

>Making no effort to control who comes here is irresponsible, because of course if there's a country that doesn't even try to vet you, and would feel guilty making you leave, of course criminals would be excited to go there.

No one is talking about making no effort to control who comes here, that's another right-wing conspiracy point not based in reality. There is a vast degree of possibility between "doing nothing" and "building a wall and sending ICE to kidnap people and shoot them in the streets." There is a degree of vetting which is reasonable and responsible and this is not it. This is paranoia and fear born of racism.