When we get our new bridge to Canada in the next few years, Detroit will have 3 border crossings, although I think they have only one office for the border patrol in the city. Michigan has 4 border crossings, now.
I really don't know much about Border Patrol, how many officers are assigned, tactics used, and so on. I know we don't have hoardes of illegals coming from Canada, though.
Here, they have to deal with a lot of drunk, American, college students. The drinking age in Canada is 19. Also, I have heard rumors that performers at Canadian strip clubs can take it all off. I've never been to one, so I can't confirm. My cousin's friends took her to a place called Danny's in Windsor for a bachelorette party prior to her marriage, and she told me the men took it all off.