That stance is very Kelo v New London.
"A Republic, if you can keep it."
The citizenship is not the root problem. The root problem is the welfare state.
Look at the American Southwest from the 1850's to the 1940's. No welfare state. No real immigration process. Just choose what side of the border you want to live on, and get on with life and being commercially self sufficient.
The dirt isn't magic. The people are the country. Replace them and you replaced the country with something different.
We've been outvoted on the welfare state issue by the left and all their imports, legal and otherwise, congratulations.
You destroy countries by destroying their cultural roots. We're a dying tree producing rotten fruit.
What made America, America is mostly gone. America is a zombie of alien (foreign) powers wearing it as a skinsuit.
The country actually died some time ago, we're watching the second death, the dying US empire with foreigners fighting over the carcass.