[quote=CA renter]We prefer to have different cultures, governments, economies, etc. so that people can choose something other than what they currently have. Migration has always been a part of human history, and I would never want it to be otherwise, but eliminating borders and consolidating governments, currencies, trade rules, economies, religious preferences, ethnicities, (even races) etc. is not a positive thing, IMO.
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Open borders won’t eliminate diversity in the way that you’re thinking. The US is very regionally diverse, yet has open borders between states.
The EU is also reasonably diverse and has open borders for citizens of any EU country. European borders were also practically open between the Napoleonic Wars and WW I. We only started putting up real walls in the early 1900s.