During the recent American elections, the most eye-catching graphics were the individual county tallies.
These showed that even when states appeared to be overwhelmingly Republican red, some still "flipped" to the Democrats on the strength of a smaller number of blue squares.
The trick? These azure islands denoted population clusters in cities like Detroit, Pittsburgh, Atlanta, and Phoenix.
The left-right chasm between urbanised Americans and the more sparsely distributed rural-regional ones was there to see in primary colours.
But the division itself was neither new, nor especially American.
Across England's industrial north, British Labour's Euro-centric cosmopolitanism cut little ice in the Brexit referendum of 2016, the same year once rusted-on working class Democrats first broke for Trump.