It's thousands upon thousands of jobs, and these people depend on it. Enough said.
And a unified pro-coal message from the national democratic party could help get KY and IN into battleground territory, get NC into Lean/Likely D territory, keep OH/PA from continuing in any republican trend they may or may not have, and maybe make up some ground in parts of Tennessee and Oklahoma. So Democrats would really benefit from being pro-coal. Dem voters who are against coal would just hold their nose and vote for the party anyways. I mean, who else are they going to vote for? The Greens? ROFL
Even if I accepted your premise that politics is more important than the future of the planet (which I don't), this is a terrible idea for many reasons:
1.
Only 31% of Americans and only 21% of Democrats think there should be "more emphasis" on coal.2. Those coal jobs are
NEVER COMING BACK. The price of coal energy will simply never be able to compete with the price of natural gas thanks to fracking. It's not because of the evil EPA and their regulations.
3. Democrats in Appalachia are much, much more socially conservative than the rest of the country. They won't be coming back to the Dems just because of coal.
I have to assume you are pretty ignorant on this subject, because you seem to believe that if the Democrats suddenly became pro-coal all those jobs would magically come back and everyone in coal country would be happy again. I hate to break it to you, but that's not how it works.