Earlier quoted context omitted.
I agree that no one who is reasonable thinks that Americans who travel to Canada get to exercise the rights they hold as Americans in America. But is having a concealed carry permit in your wallet a reasonable indication that you have a gun on your person or in your vehicle? Statistically, in the US, CC permit holders are the most law abiding group in the country.
Let’s imagine, hypothetically, that a visitor came to the US and had a permit from their country of origin allowing them to own and travel with slaves. Would border patrol be justified in giving them extra scrutiny to see if they might have one with them?
Assuming by default that somebody would break the law, just because you politically disagree with them, is not justified. As said above, CC holders are among the most law-abiding citizens (this is true in my country too). They're aware of the laws governing their permit and assuming by default that they'd break other countries' laws is preposterous. You don't just forget that you're carrying when you travel abroad or by airplane. And you sure as hell don't do something as idiotic as that, with the accompanying consequences, intentionally.