We already know Hillary plans to continue Obama's war on coal. Coal isn't, or rather shouldn't be, a dying business. But it is, and it's dying because of politics. At a time when politicians keep saying they want to create jobs and improve the general welfare, why would they be attacking a healthy industry? Yes, natural gas has become cheaper and more plentiful - but only because of fracking, and the people seeking to shutter coal are also trying to end fracking. So this is not strictly an economic consideration, there are political currents swirling everywhere.
As I drive my son to college in Ohio, I drive through coal country. Billboards about this war have been up for the last 3 years. The job losses are mounting. Some regions of PA and WV are starting to hurt severely because of this war. It's a political war, and it's driven by a lobby group with significant access to the current administration. Coal has long been one industry the US could rely on to produce energy when other methods faced economic uncertainty due to politics or economics. That is changing, and yet 4 years ago, we were told there was no threat. But even as other nations open coal fired plants, the US shutters its plants because of political, not just economic, realities.