In this page, it shows two maps. Both maps are value by alpha maps. It is composed of two layers. One layer is for the ordinary map, showing one property with different colors. The other uses another column and hence determines alpha. The first is about 2016 continental USA election result on county level. The second is about 2012 continental USA election result on county level.
In this map, blue means democraticians take advantage while red means republicians take advantage. The transparency of a place means its votes. If a county has more votes, then it is brighter.Besides, I showed the boundaries.
This map uses the same color system with the previous one. The difference is that the boundary is not shown up and this one looks better. I think one weakness of my map is I didn't show the categories well. Because the readers cannot get a specific data value from my maps.