When u allow immigration, u will increase the votes for the left wing parties.Why/how? The immigrant cannot join the white supremacists/ku klux klan/salafists/wahabis/ISIS/bajrang dal/shiv sena/ etc unless he belongs to their tribe. Generally the migrant will join the left wing labour/socialist/communist/liberal,etc.
So when the right wing parties of the west [conservatives/ republicans] goes in to wage war and destroy countries they create immigrant votes for the left wing [labour/ democrat].
If we achieve more than 50% migrants in a country then we can get a long term government for the left wing !! Then we can integrate nations into blocs or unions like European union , or ASEAN etc. Uniting these blocs will give us a one world order/government or a global village .