I wonder why my immigrant friends get so passionate about American politics. I find it mostly boring.
I think you’re not describing real political passion or engagement, though — Americans can get quite worked up about politics but we’re not all that engaged, or passionate enough to lobby for real change. Politics serve as signs of tribal affiliation and self-identity, and sometimes as a way to bludgeon other people. In that sense talking about politics is similar to, and as pointless as, arguing about sports. We (Americans) actually don’t show much real engagement if you look at voter turnout.
I found it interested because so little of it happened in Canada. But yes, I mistook it for real political involvement, but you're right, it's mostly banter. That said, I would say more Americans are at least aware of the political issue of the day, where in Canada many people just didn't care.
My other pet theory is that Canadians get more than enough politics from Canadian coverage of US politics (it's often 30%+ of news coverage) so they feel little urge to do the same with domestic politics.
I actually liked the US approach when I first arrived - "how great! everyone is passionate about politics!". I find it somewhat draining now. There is almost no part of life (work, friends, random strangers) where politics doesn't come up.