The most dominant theme from the 2018 midterm elections was the Democratic Party’s capturing of suburban U.S. House districts. From Atlanta to Detroit to Minneapolis to Denver, the Democrats made gains around metro areas.
But those vote swings tell a bigger story, according to an analysis of key counties through the lens of the American Communities Project. In short, the densely populated Urban Suburb counties in southern states increasingly look like their northern counterparts in terms of population, culture, and election results and that could have much bigger impacts in 2020 and beyond.
Link Between Counties’ Population Surges and Vote Swings
A few weeks ago, I traveled with NBC News’s “Meet The Press” to Cobb County, Georgia to examine the changes in vote results over recent elections. On Sunday, “Meet The Press” aired the Data Download segment that showed our findings. (I wrote an accompanying piece about the changing face of Cobb.)
But outside of Cobb — and Georgia — you can see similar shifts in population growth and vote swings in the last two presidential races.
|County||Pop Growth Since 2010||2012 Pres. Result Margin||2016 Pres. Result Margin||Vote Change|
|Cobb, GA||9.8%||R +12||D +2||D +14|
|Gwinnett, GA||14.3%||R +9||D +6||D +15|
|Durham, NC||15.4%||D +53||D +60||D +7|
|Charleston, SC||14.6%||D +2||D +8||D +6|
|National||5.5%||D +4||D +2||D -2|
Durham is a bit of an outlier on this list. The home of Duke University was already solidly Democratic before 2016, but the swing is still noteworthy. Republican Donald Trump actually won North Carolina by a larger margin than Republican Mitt Romney did in 2012. Despite that, Durham moved more Democratic in 2016.
More noteworthy, all these Urban Suburbs moved to become more Democratic in 2016, even as the overall national popular vote became less Democratic.
Migration Patterns Show Many Outsiders Moving In
What’s driving the changes? The population growth numbers are significant, double-digits (or very close to) in every case. Perhaps more significant is the kind of places fueling those changes. As noted in the NBC News story about Cobb, many of the new residents in these counties are coming from outside the area and the state, according to Census data. They are also coming from places that lean left politically.
Every year the Census measures “county-to-county migration flows” that look at population moves into and out of every county in the country and where those people come from and move to. Those locations for “net inflows” in these Urban Suburb counties are telling.
In Gwinnett’s case, 18 of the 20 biggest net population inflows came from counties outside of Georgia, including reliably Democratic voting Big Cities such as Manhattan (New York), Kings (Brooklyn), Los Angeles, Milwaukee, and Wayne (Detroit).
For Durham, 13 of the 20 biggest net population inflows came from out-of-state counties, including people from Big Cities, such as Queens, Kings (Brooklyn), Los Angeles, and Marion (Indianapolis).
In Charleston, 17 of the top 20 net inflows came from counties outside the state, including urban areas like Philadelphia, Honolulu, Fairfax (Virginia), and Hartford (Connecticut).
More Political Battlegrounds Forming in the South
Those inflow counties stand out for a couple of reasons. First, they are not southern communities. Second, they are all solidly Democratic and voted for Hillary Clinton in 2016.
In other words, these data present more examples of the sorting phenomenon that’s remaking the country. People from big urban areas appear to be moving to other big urban areas. And that impacts the economies and cultures of those places as well as the votes they produce.
The data suggest the Urban Suburbs are growing more uniform — and that could ultimately affect presidential politics substantially and the Electoral College if such uniformity drifts southward.
Republicans are already concerned about Georgia becoming a battleground. But together, Georgia, North Carolina and South Carolina hold 40 electoral votes — and they are still adding population faster than the nation at large.