"We get the "Ohhhh, you're American...snicker..." or people are pissed at me for what America is doing. How is that rational?"

It's actually perfectly rational. Your country voted in the current government, they are not dictators, they did not seize power, you and everyone else in the US, let them in. If the Canadian government were doing something awful, I would accept responsibilty for it, because I live in a democratic country and therefore had some say in what government was chosen. To say that I didn't would be a cop out. Like it or not you are the government you choose.