I've advocated for a long time that there is no such thing as "clean coal" because with a plant in service today there is not "dirty coal". They use precipitators, low nox burners, scrubbers, and/or low sulfur coal. They tune combustion and monitor it to the nth degree.
I don't believe mercury to be the threat the left portrays. There is a lot of research that has shown environmental mercury to have been higher in the past. Coal contains so little mercury that you can take sample after sample to find just a trace of it. It doesn't show up in chemical analysis done by plants who sample their coal continuously. They have to burn tons of it to emit just a trace. If it is in the coal in traces, it was in the environment once before and we are returning just a little bit of that which was locked in coal since we can't burn all the coal for the next 500 years. My point is, it is so little and it is dispersed globally. It is nothing.
The left has added CO2 as a "pollutant" to make the case that coal is dirty. They use the term to conjure up images of dirty fatherless 12 year old boys with black lung working the underground mines in 1900. These conditions do not exist outside of the plants and mines, and inside the mines they barely exist. Additionally, nobody has been forced to work in a coal mine, they do it willingly for the money.
Dirty coal is nothing but a political BS argument.
I would offer a ditto to your statements. Their so one sided on this issue.