I agree, the biggest factor in preventing Canada "from experience the same overwhelming flood of migration as in Europe" is...well, we're not a European country.  Thank heaven for that.  But...

"Anyone who raises an objection..."  An objection to what, exactly?  We're not prompt in "returning them to the U.S."?  We have "the longest undefended border in the world"--that thing you call a "glaring loophole in the system"?  Maybe it's "people on the move from poor countries to wealthier countries"? Or, that, "We should have a National conversation"?

Conversation's already started, Rock 'n' Roll.  It's called G&M comment pages.  And...here you are!  Thanks for your contribution. 
I think.