Obama v McCain - battleground graphics

I don't find the graphics that the TV shows use very useful in understanding the state of play during a US Presidential election, so I thought I'd create some more useful diagrams. Please comment on my blog post and tell me what you think.

All projections based on fivethirtyeight.com 2008-11-04: Today's Polls and Final Election Projection: Obama 349, McCain 189. Final calls are from electoral-vote.com.

Margin bargraph

This is the most complex of the diagrams, but also potentially the most informative. Please take a moment to read the explanation below - it really should make more sense if you do :-)

• To make sense of any of this you must understand the Electoral College.
• Red states are states that went for Bush in 2004.
• Blue states are states that went for Kerry in 2004.
• The deeper the colour, the larger the 2004 margin of victory.

• States in the band with a pale blue background at the top of the diagram have been called by the networks for Obama.
• States in the band with a pale red background at the bottom of the diagram have been called by the networks for McCain.

• States to the left of the line have gone for Obama or are projected to go for Obama.
• States to the right of the line have gone for McCain or are projected to go for McCain.
• The further left or right they extend, the further the (projected) margin of victory.

• The vertical direction is measured in electoral votes
• The thicker the bar for a state is, the more electoral votes it has.
• The numbers inbetween states near the finish line mark how far that boundary is from the finish line.
• The projected winner is the person who takes the state on the finish line. This is because, by taking that state and all the other states that they have more favourable margins in, they can win the election.

• Hover over a state for more information about it.

Cartogram

This is a map of the United States, distorted so that the area covered by each state is proportional to the number of electoral votes it wields. Paler states with names in black have not been called, and are shaded according to what polls project; darker states with names in white are called states. Many thanks to Michael Gastner and M. E. J. Newman for the polygon data that drives this cartogram.

Scattergrams

The scattergram above compares the performance of 538.com's margin projections with the real margins for called states.

The scattergram above compares the 2008 margins of victory with those of 2004.

Paul Crowley