Buttigieg's plan to repopulate depressed rural areas with immigrants reminds one of old Soviet schemes to ship people to Siberia to stimulate the economy there.
"Here's the problem. If you give government a job to do, even one that seems justified in the abstract, it will use its power to make a terrible mess in practice."
It's impossible to calculate the cost and benefit immigration without considering psychic profit and loss. And the government definitely is in no position to make any calculations at all.
Tucker Carlson seems to believe that if it weren't for immigrants, America would be dominated by religiously devout, tradition-minded, liberty-loving Americans in every corner of the nation.
The freedom of association argument is a strong argument against open borders and thus libertarians are not necessarily committed to unrestricted immigration.