If we are to make an immigration reform, we need to understand how adapting new citizens work in a polis platform, or a democracy.
According to Aristotle, who is actually more democratic than Plato, there is a control mechanism in the system. The control mechanism is the citizenship itself. According to his words. A city state (ancient democracies as Athens and other city states) will need citizens from time to time. If a polis really needs it, they can adopt new.
His point is; it takes time for at new family to settle and adopt the new nations ideas and culture. So in practise a new citizen is in a kind of trial period in the first thirty years.
If he or she makes a wrong turn, he loses his citizenship again. This travels in families. So if son of a new immigrant, or the son of a son makes a wrong turn, and disrespecst his new country, he is to lose his citizenship.
According to Aristotle it takes around three to four generations before a new family of citizens are adopted in their new homeland.
So what are the rules they are to abide by?
First of all, they should abide by the law. If they steal, rapes, or make other kinds of criminal actions, they are to lose their citizenship immideatly.
Secondly, they are to attend and adhere to the principles of the running democratic processes. In Athens, all free men was a part of the ruling of the city. The supreme ruler were the people itself.
So a new citizen should be a part of the political process. This is a bit more difficult today, where much fever persons are actually a part of the political process that runs the state. So another milder form of control should be envisioned.
People should vote, perhaps attend political rallies, try themselves at the different institution of democracy.
But, as I am a Grundtvigian. I think there is another much more important principle that should be the real basic line for a citizen. He or she should a part of soul of the people. We are all one, but we are also citizens in nations. A new citizen should feel a part of the nation and act as such a one in practical life.
G-d bless United States of America.