I saw a reference to this earlier, then was struck by a talking head on Fox arguing that we should only admit immigrants who share our values.
Some random thoughts:
- there's no universal rule applicable. Canadians believe you need to speak either English or Franch, but Americans wouldn't agree to an English-Spanish rule. Greeks are strong on religion, but that's no longer that important in most other countries.
- adding some other countries, such as China, Russia, India, Indonesia, Nigeria, etc. would have further expanded our horizons.
- in the past, many didn't believe that Irish Catholic immigrants could be good Americans: they shared neither birthplace, religion, nor customs with the then-current Americans. That was even more true when the time came to admit immigrants from eastern Europe and Italy.
- when we look in detail at current "Americans" we find groups which don't share our customs and values but share the language (i.e. Old Order Mennonites,Hasidic Jews) and some which don't share the language but are somewhat closer in values, if not customs (some Latinos)