What point does meyer jacobstein make about resistance to immigration throughout american history?

Meyer Jacobstein is against the resistance to immigration. In particular, he opposses to the Immigration Act of 1924". In reference to this and similar laws, he states that nothing is more un-american than, in the land where the Constitution says that all men are created equal,  to write a law against immigration that is un-scientific, evil and un-american.

answer; the period of time known as the middle ages;