Wow, some really interesting edge cases in there that require serious thought. US border guards might deny you entry if you admit to previous cannabis use - for them "A confession is as good as a conviction". So you can do something that is perfectly legal in Canada, then a month later be denied entry to the US for doing it. If you work at a 100% legal Government-run Cannabis store and want to go to the US for a holi…
Once on a connecting flight so I wasn't even wanting to leave the airport. At the time I was working for a highly regarded company and going on to do some work for CBC in Toronto. I had flown in on business class and my smile, polite British English, white skin, smart clothes, clean passport and squeaky clean criminal record should have given me a free pass. I wasn't even carrying any highly unusual electronic hardware. And no I had not been a member of the 'communist party'.
As I saw it there was just a problem of 'customer service'. The mentality of border guards should be to welcome guests to the country and not treat everyone as a criminal.
As a non-U.S. person I am like a lot of people that just see the U.S. as not the place to want to go to. I know that most Americans lay on fantastic hospitality for visitors, welcoming you into their homes and looking out for you. But the hostile border guards obfuscate that.
Canada is the far more preferable destination, whether you want to be stoned all day or not matters little really, the legalisation of weed sends a signal that Canada is the much more welcoming place to go.
Tourism matters, I do wonder how much tourist trade the U.S. misses out on due to the negative perception the world has of the place.