It was under Bill Clinton that Coal Country finally started consistently trending away from the Democrats. For example, West Virginia has trended Republican in every Presidential election since 1992 and Kentucky since 1996; Democrats also started shedding counties in southwestern Pennsylvania in 2000.
JA is on the money here.... and here is a T-Shirt that closely resembles one that I still wear given to me by a 3rd Generation Coal Miner in Ohio back in 1993.
The failure of Bill Clinton's Administration to intervene during the 1993 last ditch effort from the United Mine Workers of America to protect their membership from the Operators owning up Non-Union Mines side by side with Union Mines in Appalachia ("Double Breasting"), as well as major investments in Non-Union "Open Pit" Coal Mines in places like Montana, Wyoming, and elsewhere in the Mountain West, was where the Democratic Party started hemorrhaging votes in Appalachian Coal Country, well before the whole Al Gore, Climate Change, "War on Coal" narrative developed.
So, imagine a scenario where one of the most powerful Unions in the United States, in one of the most dangerous occupations for a Century, that had stood up against both Democratic and Republican Presidential Administrations alike, after 12 consecutive years of Republican rule does the equivalent of a final last stand (Although the '93 Strike was an outgrowth of the '89 Pittston Strike in the Coal fields), when the bosses are aggressively moving to destroy the UMW/UMWA, and the Democratic President Bill Clinton is MIA/AWOL....
Hell--- Bill Clinton did better with Timber Country in the PacNW, even with his "Option Nine" than he did with the Coal Miners of Appalachia.
There is currently no such thing as a Union Coal Mine in Kentucky..... and there is still quite a bit of Coal getting mined in SouthEastern Kentucky.
If a Democratic President won't even stand up for Coal Miners, two decades prior to the collapse of Coal as an energy resource, than why should or would Union Retirees, or Non-Union Coal Miners in Appalachia vote on the basis of their economic interests, and instead begin shifting towards Pub Pres candidates on the basis of other items?