> It's unethical to require people from other countries that want to enter the US to follow certain, well established, legal protocols before they enter?
The contents of letter state that it is a reaction to the recent news that babies and toddlers of immigrants crossing the border illegally are being separated from their parents in the hundreds. We have no evidence that these parents have been charged with violent or other crimes of a nature that might justify the separation for the children's safety.
In no way does the letter assert that it supports illegal immigration, as I think your comment suggests. Rather, the letter accuses ICE of inhumane treatment of children in a way that violates international law.
So the letter cosigners might very well be strongly against illegal immigration. I am strongly against homicide, for instance. That being said, I would like our prisons to treat convicted murderers in a humane way. Just because I am against murder, it doesn't mean I want prisoners to be water boarded or starved or what have you.