Right to move.
Migration is a natural phenomenon. Since the very beginning of life, beings are, intentionally or unintentionally, migrating. Besides obstacles, life achieved even the toughest places on our planet, like volcanos and polar areas. But this movement is not always pacifical.
Anytime when better conditions of life are imagined in a distinct site, human migration occurs. Migration has taken humanity out of Africa to Europe, Asia, Oceania and, at lest,
After some thousands of decades, all continents were occupied by humans seeking
more resources as hunting, gathering, land, minerals or energy. America
Many obstacles were always found by migrators, firstly, natural ones as mountains, rivers, deserts and seas. As societies have become sedentary, migrants groups have been finding extra difficulties because they are often seen as foes by the settled ones, who do not intend to share their resources.
Migration, aside, is able to assure surviving of specie. Challenges to life, especially climate changes, can be overcome by migrating to a place where weather becomes acceptable.
As much as freedom of trade and investments is claimed to be an imperative, the possibility of free movement of people must prevails. Liberalization as Globalization, using all the advanced technology of communication and transport, are getting possible to easily move wealth around earth. National borders are getting less and less significant to investments. Thus, the same must apply to people. There is no reasonable fundament to maintain restrictions to people movement whether they need to follow the economic path cemented by wealth flowing.
Migration is as natural as trade. Besides the difficulties, it is in the root of life. Obstacles imposed by states to it are not only irrational but unfair, as wealth is free to move and settle wherever it judges is interesting. How could the prehistorical men be stopped to follow the hunting cattle?