Monthly Archives: October 2005

Margin Swings & Trends

Swing Map
Trend Map

Upon a suggestion from Alcon, I have created swing maps by county between the 2000 and 2004 elections. These maps describe the change in margin percentage (i.e. the difference between the Democratic vote percentage and the Republican vote percentage) between the 2000 election and the 2004 election. The maps may be found on the state summary pages (example). These maps show the change in support on a percentage basis for each county between the successive elections. In the New Jersey map to the right, the margin in every county swung towards Bush. The very light blue represents a change of < 5%, the light blue between 5% and 10%, the blue between 10% and 15%, and the dark blue 15% to 20% (see the Atlas Master Key for complete color and margin assignments).

(edit: 20051101) A second set of maps have been produced that show the county “trend” between the 2000 and 2004 elections. The trend map differs from the swing map in that the margin change is normalized to the nation-wide margin change (i.e. MarginCounty2004 – MarginNational2004 – (MarginCounty2000 – MarginNational2000) where each Margin is (VoteD – VoteR)/TotalVote). So, as an example, consider Hunterdon County, New Jersey:

Year VoteD VoteR TotalVote Margin Margin%
2004 26,050 39,888 66,680 13,838 20.75%
2000 21,387 32,210 56,455 10,823 19.17%
Swing 4,663 7,678 10,225 3,015 1.58%
2004 59,028,439 62,040,610 122,300,762 3,012,171 2.46%
2000 51,003,926 50,460,110 105,417,258 543,816 0.52%
Swing 8,024,516 11,580,500 16,883,504 3,555,987 2.98%
County Trend 2000 to 2004
(County Swing – National Swing) 1.40%

To calculate the swing in Hunterdon County, subtract the margin percentage in 2000 from the margin percentage in 2004 -> an increase for the Republicans of 1.58%. Therefore the swing map shows Hunterdon County for Republican by < 5%. The trend is a normalization of the county margin change based on the national margin change. The trend is calculated by subracting the national margin swing from the county margin swing. Since the margin for Republican nationwide increased by 2.98% and the margin in Hunterdon County swung a smaller 1.58% towards the Republicans, the trend in Hunterdon County is 1.40% towards the Democrats. The map therefore shows Hunterdon County for Democratic by < 5%.

Feedback is welcome on all aspects of the feature (color selection, number of bins, whether it is useful or interesting, etc.).

Presidential Electors 2004

Marilyn Bose, Julie Hosch, Belma Huebner, Don Kass, Don Racheter, Dorothy Schlitter, Wanda Sears… these names don’t ring a bell? They won the election for Presidential Electors in the state of Iowa in 2004. These are the candidates the citizens of Iowa actually voted for when they cast their ballot for George W. Bush for President in the 2004 General Election. As stated in Article II Section I of the United States Constitution that Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress. Today, all states except two (Nebraska and Maine) appoint an entire electoral slate through the use of a state-wide popular vote. The aforementioned exceptions in Maine and Nebraska vary only slightly from this model, choosing electors based on the Congressional District Method.

Some 3,400 Presidential Electors nation-wide have been added to the Atlas database and the election results for Presidential Electors is accessible via the link on any state summary page (Example: Iowa Electors 2004). Electors included are all those pledged to a candidate that was ballot-qualified in at least one state (electors for qualified write-in candidates that had no ballot access are not included).