From their perspective, this should require no effort; it is forcing them to change which requires effort.
Of course I want the use of coal to stop. But you need to reckon with these kinds of human factors if you want to effect change peacefully.
This is where Clinton failed. Having a documented plan to spend billions (somewhere on the order of 10 years of salary per miner, from numbers I could glean elsewhere in this discussion) doesn't make an impression when you have well-documented sound bites claiming that you intend to put them "out of business".