I never said I wanted to "by and large" exclude non-Mexican immigration. The reality is that Mexico does border the US and much of the immigration problem does seem to stem from Mexican immigration - I find little concern about Canadian immigration (legal or otherwise) by contrast. More realistic limits on legal Mexican immigration would seem to solve the issues surrounding illegal immigrants.
“I find little concern about Canadian immigration (legal or otherwise) by contrast.”
The reason for that would be that there is so little of either. Canada is a country of only 20 million.