Not quite as red as it appears

The following map has become quite popular amongst right-wing bloggers, seemingly to demonstrate that the country is more “red” (or right-leaning) than the last election’s results would indicated.

It looks pretty impressive, doesn’t it? But it really doesn’t tell the whole story. The above map is a winner-take-all representation for each county, which is okay except it’s not a very accurate gauge of the “temperature” of the nation. Here’s how the map would look based on actual voting percentages.

Not quite so stark anymore is it. No longer are there large areas of red with only blue fringes. But wait, there’s more. Mark Newman, Department of Physics and Center for the Study of Complex Systems, University of Michigan, explains.

Looking at [the top map], it gives the impression that the Republicans won the election handily, since there is rather more red on the map than there is blue. In fact, however, the reverse is true – the Democrats won by a substantial margin. The explanation for this apparent paradox, as pointed out by many people, is that the map fails to take account of the population distribution. It fails to allow for the fact that the population of the red states is on average significantly lower than that of the blue ones. The blue may be small in area, but they represent a large number of voters, which is what matters in an election.

We can correct for this by making use of a cartogram, a map in which the sizes of states are rescaled according to their population. That is, states are drawn with size proportional not to their acreage but to the number of their inhabitants, states with more people appearing larger than states with fewer, regardless of their actual area on the ground. On such a map, for example, the state of Rhode Island, with its 1.1 million inhabitants, would appear about twice the size of Wyoming, which has half a million, even though Wyoming has 60 times the acreage of Rhode Island.

So, here’s the result when you take the top map and adjust for population:

And here’s the result when you take the proportional voting margins (the second map) and adjust for population:

It helps to put things in the proper perspective.