Don't know about Canada specifically but as far as i know asylum laws are about having a valid reason, so being from a specific place is less often a valid reason than being from a minority (can also be religious or ethnical) or having certain political views. They would likely sooner accept for example Amish , indigenous or democratic people only before just accepting anyone from the US. I think you're wrong in believing that is unlikely to happen if you see how anyone with a Hispanic demeanor is being treated right now.