English: Cartogram of the Electoral Vote for US President in 2004, 2008 and the swing between the two. The 113 vote swing accounts for Kerry's 251 votes plus the one rogue Minnesota vote for John Edwards. Each square represents one electoral vote.

The population density of the 50 states varies by three orders of magnitude (from NJ with nearly 1,200 people per square mile, to AK with roughly 1 1/4 people per sq mi). Because of that huge variation, a regular map of the US that is typically used to present electoral vote results can convey a very skewed impression of the outcome where sparsely populated states appear overrepresented and densely populated states appear underrepresented. The cartogram approach of this image eliminates that problem by presenting the area of each state in an exact one-to-one correspondence with its number of electoral votes. But this is achieved at the cost of introducing distortions to the actual shape of each state and their positioning in relation to each other.