This is mentioned in the article but worth emphasising: the graphic shows is coloured by the proportion of the local population that supports secession, not by absolute numbers. Therefore, a state that is coloured mostly pink still may have very little absolute support, assuming that they're mostly rural areas.

In fact, since rural counties tend to be physical larger, I'm not convinced a map like this is the best way to present the data anyway, since it could be misleading.

The graphic is trying to show the distribution of support for secession by state.

I'd say that a map is exactly the right way to present the data.

I think the gp is alluding to a cartogram-style map:

http://en.wikipedia.org/wiki/Cartogram

Exactly. A recent example I saw of this was the Princeton Election Consortium, http://election.princeton.edu/electoral-college-map/

This graphic doesn't take into account the gaming going on. I.e., people from other states wanting Texas to secede.