Monoculture is the quickest route to extinction. Rotate your crops.
Bullsh*t,
Inbreeding leads to weakness of a species. The melting pot of Americanism is where people from all over the world assimilate into what is purely American history, values, and ideals. Bring them in from all over the world, orderly and fully committed to those ideals. If they want to adhere to Chinese ideas
go to China
.and so on. Multiculturalism seeks to divide, denigrate, and Balkanize. That is not the American Way. But, it is where Progressivism leads.