I think this analysis ignores that most coal power plants are located in remote areas, often on high ridges outside of polluted air basins unlike gasoline automobiles. Moreover, natural gas power plants put far fewer traditional emissions than gasoline engines on a per mile basis. Electric cars don't have tailpipe emissions. 

I think the national obsession over climate change is unhealthy, when we should be more concerned about controlling urban emissions in air basins that significantly out of compliance. Climate change emissions have the lowest impact on the environment compared to nearly any other form of pollution.