I get the joke, but it's pretty commonly known that hall road is a division line in terms of a lot of things. The history behind it is interesting, since it's basically the marker of what could be considered a second white flight in the northern suburbs, when people who originally moved to areas like Warren and St. Clair Shores decided they hadn't moved far enough once more people moved to those areas.

But this is true everywhere. I noticed the ideological divides almost down to the street when I lived in Louisville, Seattle, and Phoenix especially. Detroit's history of it is just way more emphasized.