cartographic variations on the presidential election 2000 theme

"The American people have now spoken, but it's going to take a little while to determine exactly what they said."
- former President Bill Clinton.

"Celebrating America's Spirit Together"
Theme of the 54th inauguration - new President George W Bush.

A map is a popular graphic device to communicate election results. Usually choropleth maps are used to portray voting behavior. Typical examples are the maps below from CNN's and NBC's Web site, or the ones that were shown on all TV stations during election night (Tuesday Nov.7 2000). Unfortunately, mapping totals or absolute values per enumeration unit (e.g. electoral or individual votes by state) is unacceptable by sound cartographic standards. The enumeration units (e.g. states) are unequal in area, thus might give the reader a false impression of the mapped data distribution.  A person not familiar with the US voting system might wrongly assume that Gov. G.W. Bush is winning the election, considering that two thirds of the US is shaded in red. Indeed, Bush won 29 of the 51 states (at the time of writing), but only 246 of the electoral votes (48,783,510 votes). Gore on the other hand scored only in 20 states, but received 260 of the crucial electoral votes instead (48,976,148 votes).
 
traditional choropleth map(© by CNN) another traditional choropleth map (© by NBC)
The two-variable contiguous area cartogram on the left depicts enumeration units proportionally scaled to the data that they represent.  In addition, traditional choropleth shading is applied, showing the States won by each candidate. The size of each state is transformed based on the magnitude of electoral votes, emphasizing the variable that carries the crucial election information.   The size of the red areas has decreased dramatically. The length of the bars in the legend refers to the amount of observations falling in each category (# of won states per candidate).
Input data for a cartogram is never classified. The cartogram is therefore one of the truest form of quantitative mapping. This is why a cartogram legend should include a continuous tone color bar, showing a continuous data range from minimum to maximum value (not labeled). The overlay with a categorical variable map (Gore, Bush, or undecided wins) would typically require a qualitative color scheme, showing differences in kind. For example a discrete, classed legend type, with three distinct color hues for each case, e.g. blue, red and white.
contiguous cartogram based on electorate votes 
(© by sara i fabrikant)
In this value-by-area map, the size of each enumeration unit is scaled based on the magnitude of total population within each State (1997 data).  Again, the size of the red areas has decreased dramatically.  Overall, the two cartograms look very similar, still slight variations are distinguishable.  This is not surprising, as the amount of electoral votes is based on the magnitude of inhabitants in each State. The length of the bars in the legend refers to amount of observations falling in each category (# of won states per candidate).
contiguous cartogram based on total population 
(© by sara i fabrikant)
 
This cartogram shows an entirely different picture of the presidential election.  The states are scaled according to population density (1997 data).  East Coast States clearly dominate the scene, with the District of Columbia (D.C.) leading the pack.
As Karen S. Eisenhart from Boulder, CO notes: "This is interesting in light of the fact that the District of Columbia has no representation in Congress. Recently, they have proposed to change the slogan on their license plates to taxation without representation."
contiguous cartogram based on population density
(© by sara i fabrikant)

Data Source: ESRI ArcView 3.2 data CD: shapefiles and US population data attributes 1990/1997.


Curious to explore more of the fascinating world of cartograms? Click here for a hands-on example provided by Adrian Herzog's cartogram applet MApresso. Also check out this contiguous cartgram animation. A non-contiguous cartogram animation is provided by Keith Clarke. More on election maps...

© by sara irina fabrikant, 2000
www.geog.ucsb.edu/~sara/html/mapping/election/map.html