JJ, An interesting question. Apparently, N.C. Snyder thinks not. I think what the historical record shows is that all nations will slip backwards when a threat is severe enough as Motley points out below.  My guess is Snyder is trying to make some kind of comparison to the Germans rounding up Jews and the US enforcing its legitimate and legal immigration laws. If  a nation can defend it borders and territorial claims then it has the right to say who enters and who leaves those borders as long as the determination of who stays and goes is within its laws.

I for one can understand the plan of building a wall to control who enters and who leaves and simultaneously determine who stays and who goes. I would think a winning compromise for both sides would be to agree on building the wall and in return, negotiating the humanitarian policies/laws of who stays/goes. Personally, I view Trump's policy more right than the current democratic/progressive stand.  "Humanitarian amnesty for a wall!"