Dirty Coal

I came across this ad via Joseph Romm’s excellent post – as Joe said:

[the] ad violates a central rule of messaging, rhetoric, and psychology: Don’t keep repeating a strong word the other side is trying to push. That is not just a basic tenet of the 25-century old art of persuasion, but a well-demonstrated principle of modern psychology

Dirty coal is the only kind of coal there is, anything else is just unicorns.