## Who’s winning on election night?

By: on November 3, 2008

I find the maps and charts that the TV networks provide nearly useless for understanding the state of play during an election night, so I’ve taken to designing my own diagrams. For tomorrow’s Presidential elections, I’ve turned the projections on fivethirtyeight.com into a graph which illustrates the likely outcome of the election and the paths to victory for the two candidates:

The x-axis represents the projected margin of victory – leftwards for Obama, rightwards for McCain. The y-axis represents electoral votes. The states are ordered by margin of victory.

From this graph you can immediately see that Obama is projected to take all the Kerry states by a margin of 6.9% or more, and the Bush states Iowa and New Mexico appear to be firmly in his pocket with projected margins of 11.0% and 8.6%. That puts him 5 EVs from the middle line – a draw – and thus 6 EVs from victory. So if Obama wins all of these states plus any other state with 6 EVs or more – or any two other states – he wins the election.

That’s useful for now, but what about during election night itself? You can see a chart that says something like Kerry is 10 EVs ahead of Bush, but that doesn’t help clarify which of them is really doing better – if they’ve called New York a whole load of New England states while a lot of Southern states are still waiting to announce, then the Democratic lead might be no more than you would expect, or it might even be less.

Here’s a fantasy scenario what I have lined up for the Presidential elections tomorrow [removed – the final result is now online]. When they call states, I’ll move them to the top or bottom of the graph as appropriate. The area inbetween the called states is the remaining battleground – and anyone who can win all the states up to and across the finish line can win the election.

I will also be maintaining a scattergram showing how the projections have done against reality, and a cartogram illustrating the electoral college.

This is tricky information to represent in a single graph, so any ideas for improvements will be gratefully received – thanks!