As you may have noted before, this familiar map always gives the impression that the Republicans won, whatever the result of the election. The U.S. looks like it has a vast heartland dominated by honest-to-God Republicans, while a minority of Democrats gather in plush lounges around the edges of the country, sipping cocktails and talking down America. This is because (as discussed previously) Republicans tend to do better in more rural states that cover larger geographic areas, while Democrats do better in more urbanised states, with plenty of voters but less space. In other words, the conventional political map fails to take account of population distribution; hence the dominance of red.
Of course, a map that gives an impression at odds with reality is by definition a bad map. While it may be impossible to draw a map that perfectly corresponds with America's politics, it turns out to be instructive to look at different ways to do it, as Mark Newman, at the University of Michigan, demonstrates in a fascinating post. He has created a map in which the states are sized roughly according to the size of their populations. In this map, Rhode Island is twice the size of Wyoming, because despite being 1/60 as big it has twice as many inhabitants.
(Read the whole post, complete with several further refinements of this map.)