The size of state on map is not proportional to number of votes,
so it is not a very good visualization of data.
It is quite strange that nobody created "dot map" with the same data,
that is much better for understanding the data visually...
United States of America: Presidential elections since 1789 (Maps)
@Wikipedia, by county
This picture is even more misleading, since most Democrats-wins are in urban centers that are much more populated...
This is much more accurate 'cartogram', but much less pretty