Coal already is becoming increasingly impolitic, even for the uses to which we now put it. Most Americans already want an end to coal in electricity generation, according to media interpretations of polling data. And the Democrats seemingly want policies destined to enforce rolling blackouts as a regular part of life for most Americans, or at least those few that still could afford any electricity (at much higher prices) after paying their taxes and buying some food.
So I really do not foresee the proliferation of coal-to-oil technologies because of political, not economic, thermodynamic, or technological constraints. The American people through their elected Democrat (and some Republican) representatives clearly demand drastic cuts in the fuel usage of their fellow compatriots and pine for the consequent unending economic depression. Political problems similarly prohibit the extraction and refining of petroleum within most unexploited sections of the American territory. Witness the ongoing fracas over the technologically novel possibility of oil drilling in the icy Chuchki Sea.
Most Americans do NOT want this garbage; they might say they do, but they want their cars more. When they find out global warming is a hoax, they will DEMAND more drilling, more refineries, and will tell all you dufeses to shove it.