Not that it’s necessary but thats what our demographics were before the massive changes so I believe we could go back to that and then just maintain it. After that if the country’s demographics change organically than so be it.

@Lukdnuke Nah too late for that, I think maintaining demographics as they are would be difficult enough. I could argue that the demographics after those 1965 changes were more natural than you would think as the new immigration laws didn't favour Europeans as they did before, and thus the White American population was no longer bolstered. Regardless, the positives may still outweigh the negatives, there are many skilled immigrants that were allowed to enter the country as a result of the change in immigration policy. To me, demographics don't really matter, as long as skilled workers are entering the country and assimilate enough to work effectively.

I'll address your other points too:

2. As America becomes more developed and wealthier, birth rates will inevitably decline. So I guess immigrants are gonna be coming in forever, unless some fascist/communist-esque policy is implemented which just isn't an option.

3&4. I don't see excluding any country from immigration for no valid reason as an option. So we're gonna have to think beyond just straight up banning immigration from certain countries. Rather the US should work to further incentivise skilled workers from first world countries, and disincentivise illegal immigrants and less skilled workers. This could be done through new visa schemes, and a harder stance on illegal immigration as well as a narrower focus on skilled labour.