That is always true. Its called an invasion, and the rules of warfare and immigration are pretty different.
> Looking at state-to-state movement restrictions is silly because all of the said population is under the same federal jurisdiction, same constitution, and same supreme court system.
When a foreigner enters the us, he is under the same federal jurisdiction, constitution and supreme court system. There is no conflict of law. There is conflict of interest, only if you portray the issue as an us vs them.
> I can promise you that the Netherlands doesn't want 20 million far right fundamentalist christians moving there and influencing policy. San Francisco doesn't want a few million Wahhabi Saudi's saying that gays should be beheaded. Small Pacific islands don't want a few million Chinese showing up and claiming their area as new territory.
The netherlands doesn't want anything, because it's not a person. San francisco is a city, it doesn't have a will or a life. Individuals want things and do what they can to do it. If a bigot or an intolerant wants to move to San Francisco, who the hell is a government official in san francisco to forbid him to do it. Funny you mention SF that has a movement to kick out software developers and startups, because it's "destroying the culture of the city".
If 1 million saudi conservatives move to san francisco, they would pay so much money to achieve such a ridiculous demographic goal that the residents will have plenty of money to move and change another city to their own liking. That is, unless they are forbidden to do it by another government official.
And if the bigot/intolerant guy then throws acid in the face of your sister because she's wearing a skirt that's too short, for example? We see this quite often in London and other enriched European cities.
That seems quite naive, to the point of outright stupidity.
If I was a large nation state with a very large population, it would be very easy to take over another smaller nation by just migrating a huge population to that country. This was used by the USSR post-takeover in many of their satellite states.
Looking at state-to-state movement restrictions is silly because all of the said population is under the same federal jurisdiction, same constitution, and same supreme court system.
I can promise you that the Netherlands doesn't want 20 million far right fundamentalist christians moving there and influencing policy. San Francisco doesn't want a few million Wahhabi Saudi's saying that gays should be beheaded. Small Pacific islands don't want a few million Chinese showing up and claiming their area as new territory.
Free movement will have dramatic effects. Some may be positive, but you seem to steadfastly think it will not be manipulated in horrible, horrible ways by the nation states that already exist.