It was a throwaway line in FiveThirtyEight’s live blog of Thursday’s special House election in Montana.
“You can’t lose a lot of money these days,” the site’s David Wasserman wrote, “betting on a widening urban/rural gulf.”
He was responding to a comment from Nate Silver, pointing out that the Democrat in that House race was doing much worse in rural areas of the state than in urban ones — even relative to how Hillary Clinton had fared in each in November. In other words, places that backed Clinton more strongly in 2016 were more likely to move more to Democrat Rob Quist in the special election.
It’s a small effect, but it’s a noticeable one. Here’s how much each county in the state shifted to the Democratic candidate since November’s presidential election vs. how much of its population lives in a rural area (per the Census Bureau).
Overall, support for the Republican, Greg Gianforte, correlated to how rural the county was — a trend we’ve seen many times before.
But Wasserman’s point is the scale of the shift.
We can see this on a national level. If we take the relative margins of victory in each county from the year 2000 — that is, how much the county preferred the Democratic or Republican candidate relative to the nation as a whole — and compare it with how rural the county was at that point, it looks like this.
A slight trend there, but mostly a big clump in the middle of the graph.
If we plot the same data for the 2016 results (and the 2010 Census Bureau data on rural populations), the result looks like this.
Remember, this is relative voting. It’s not Donald Trump or George Bush, it’s how the county voted relative to the whole country. And if that shift wasn’t obvious, we can overlay them.
That’s the shift…