I can't speak of the political climates of the majority of the world, but at least in Europe multi-party systems aren't that uncommon, and those tend towards less of an ideological divide between the parties than the American bipartisan system, from what I've gathered.
So I'm not sure I entirely understand what you mean with the divide being more internationally palatable. "Spilling over" also doesn't imply the source is static.
I can't say if it aligns more with the divide in the rest of the world, but saying US politics "spills over" into the rest of the world makes it sound like the US is static. The parties are evolving though: maybe the US is just shifting to toward a more internationally palatable ideological divide.