I'm not joking.
The following is from Bloomberg News:
...41 percent of Americans say that if a wall is built along the Mexican border, one should also be erected on the Canadian one. And yes, the same percentage favors a wall erected along the nation's southern border...
And the reason they need the monstrosity, both North and South?
Well, according to at least one citizen it's because:
"...If you cut off one (border), they're going to come in the other way..."