US Election: The mysterious blue curve

2012 US presidential election results by county (blue for Democrat, red for Republican) 2012 US presidential election results by county (blue for Democrat, red for Republican) Kelvinsong
04 Nov
A quirk of geology has produced a strange pattern on the American voting map. What is this blue curve, and where does it come from?

Arguably, the first takeaway from studying a county map of the 2012 US presidential election is the significant influence of the USA’s dense urban cities. Over a purely geographical spread, the above map looks more like a landslide for Mitt Romney’s Republican party (red), not a comprehensive 332 – 206 electoral vote victory for the incumbent, President Barack Obama and the Democrats (blue). The high populations and therefore large number of votes from such states as California, Florida, New York, Illinois and Pennsylvania carried the 44th president back to the White House, despite the large swatches of red across such central states as Oklahoma, Utah, and West Virginia.

However, there is another curiosity on the map. In the middle of a sea of red in the southeast of the country, a thin blue line of Democrat voters can be seen curving through such states as Mississippi, Alabama, Georgia, South Carolina and North Carolina. It’s a trend seen not only in 2012, but also 2008, 2004, 2000 and into the last millennium. Why is this narrow band of voters consistently voting Democrat when their surrounding neighbours opt for the Republicans?

2012 lineThe mysterious blue line in the 2012 election counties map (Image: Kelvinsong)

The answer lies in a mix of geology and demographics. Visitors to this region one hundred million years ago (give or take a few million years) would have observed the fractured continental ‘North America’ of the Cretaceous era, divided, as it was then, into the western Laramidia landmass, and the eastern Appalachia landmass. Coastlines sat in very different locations to where they are today, and – crucially – included a large region of coral reefs off the southern edge of Appalachia, around what is now the southern foot of the Appalachian mountains, in Georgia, Alabama and South Carolina. As time passed, the shallow seas in the region dissipated, the landmasses fused into one and the coral reefs crumbled into soil.

appalachiaLate Cretaceous North America showing the landmasses of Laramidia and Appalachia (Image: Ron Blakey)

Early settlers to the US may not have fully understood this geological history, but they knew fertile land when they found it. The vast organic matter left in the soil from these ancient reefs made for excellent agriculture and, over the course of 19th century, a vast and profitable cotton business grew along this ridge marking the old Appalachian coastline.

Prior to Abraham Lincoln’s preliminary Emancipation Proclamation in 1862, abolishing slavery across the United States, such an industry would have been heavily dependent on African slaves with around four million individuals still enslaved at the passing of the Act. In the century-and-a-half that followed, despite the significant changes in society through time, this same part of the country became the spot with the highest concentrations of African-Americans – descendants and family members of former slaves – situated along the location of the old Appalachian coastline.

censusProportion of American population self-describing as ‘black’ in the 2010 census (Image: United States Census Bureau)

Thanks to the policies of 36th president, Lyndon B. Johnson – such as the 1964 Civil Rights Act – the Democratic party has, especially since the 1960s, been the party most closely aligned with African-Americans. Barack Obama collected 93 per cent of all African-American support in the 2012 presidential race, a figure which hasn't fallen below 80 per cent for decades.

Hence, despite their fellow Georgians, Mississippians and Alabamians deciding that Mitt Romney was the best man for the job, the residents of the mysterious blue curve continue to put a cross in the box of the Democrat candidate, an action traceable back to a one hundred million year old coral reef.

Share this story...

Submit to FacebookSubmit to Google PlusSubmit to Twitter

Related items

Leave a comment

ONLY registered members can leave comments and each comment is held pending authorisation before publishing. Please login or register to voice your opinion.

Geographical Week

Get the best of Geographical delivered straight to your inbox every Friday.

Subscribe Today


Aberystwyth UniversityUniversity of GreenwichThe University of Winchester




Travel the Unknown


Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • National Clean Air Day
    For National Clean Air Day, Geographical brings together stories about air pollution and the kind of solutions needed to tackle it ...
    REDD+ or Dead?
    The UN-backed REDD+ (Reducing Emissions from Deforestation and Forest Degradation) scheme, under which developing nations would be paid not to cut dow...
    The true cost of meat
    As one of the world’s biggest methane emitters, the meat industry has a lot more to concern itself with than merely dietary issues ...
    Long live the King
    It is barely half a century since the Born Free story caused the world to re-evaluate humanity’s relationship with lions. A few brief decades later,...
    London: a walk in the park
    In the 2016 London Mayoral election, the city’s natural environment was high on the agenda. Geographical asks: does the capital have a green future,...


NEVER MISS A STORY - follow Geographical

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in PLACES...


The next stage in autonomous vehicles is hoping to transform…


Geographical’s resident data cartographer presents a true picture of the…


What impact could an unprecedented incident of ‘river piracy’ have…


Norway is to undercut a mountainous peninsula to create the…


Benjmain Hennig explores global mortality with maps


Last winter’s cold conditions contributed a further influx of road…


As one of America’s biggest cities, supplying clean drinking water…


Cape Town’s Foreshore Freeway Bridge has been left unfinished for…


An interactive map highlights the shocking number of ongoing conflicts…


Repurposed NASA maps show the racial diversity (and segregation) of…


Benjamin Hennig maps Europe's public train networks


A new map of global landslide susceptibility reveals vast geographical…


For decades, scientists have been divided over how these eerily…


The first count of global tree species reveals how many…


The new ‘world’s longest flight’ now spans a distance of more…


For the Swiss, the iconic yellow postbuses are much more…


After years of inaction, could the clean-up of the Venice lagoon…


Following the recent success of New Zealand’s Whanganui river, India’s…


The UN-backed REDD+ (Reducing Emissions from Deforestation and Forest Degradation)…


Where are Europe's earthquakes located? Benjamin Hennig maps the answer