I heard an interview with Trudeau which discussed immigration. That interview gave me the epiphany of why the Left in the US wants all of these immigrants -- the Left discourages families, particularly large ones (I presume going back to Marxist ideologies), but they are on the hook for all of the entitlements like Medicare and SS (I know, SS isn't supposed to be an entitlement, but they've spent all of the money). So basically, they need working bodies in the future to support these things. It's a big house of cards that will eventually implode, but no politician (including Trump) will take it on, because it is political suicide.
Canada is worse off than we are; something of a glimpse of our future, should we continue our path.
That being said, Canada is selective in their immigrants. Whereas in the US you can get in based on family relationships due to the 1965 Immigration Act, in Canada, you actually have to show value. You are a doctor? Come on in! You are a Haitian migrant? Get in line over there, eh?