The analogy is fair. See, when it comes to your home, you expect people to leave and not come to occupy your home, most likely because it will limit your own au

The analogy is fair. See, when it comes to your home, you expect people to leave and not come to occupy your home, most likely because it will limit your own autonomy. There are borders you are not willing to cross. It is not different with countries. I think that immigration is perfectly fine until a country can absorb new people but too many people too fast is going to create troubles. I think that you can imagine very well a situation when you are kind and let somebody into your home but they now start to make their own rules - in your home. If it gets unbearable for you in your home then perhaps you can call police, but if you make such a mistake on the country level then there is less remedies - so you have to be considerably more careful. Let's imagine that four hundred million Chinese would move into US in the world without borders and now they vote into power a new political party that will prohibit all the other political parties. Why? Perhaps only because this is the only way they know about and they didn't have the time to gradually learn other political possibilities or worse they are instructed to do so by their leaders. Destruction of democratic system using democratic means is not rare. Perhaps the most known one is rise of Nazis in Germany. Most obvious recent example is rise of Putin in Russia but it also happened for example in Egypt, where Muslim Brotherhood won elections and then attempted to destroy the democratic system of Egypt to enforce sharia, and this was preempted by the events in Gaza where Muslim Brotherhood offshoot Hamas did exactly the same, but successfully. The world without borders will also mean that a malicious and well organized political force can move around the globe and take over local power using seemingly benign methods instead of military power. So while your idea sounds something to root for, it is also incredibly naive and dangerous in the real world we live in.