Coal makes up less than 40% of our electricity generation nationwide. The other 60% comes from much cleaner sources like natural gas, nuclear, and hydro. Furthermore, in the states where most EVs are sold, the proportion that comes from coal is far less than 40%.
Only if you live in the heart of coal country is it worse to drive an electric car than a gasmobile.
Besides, we should prefer to drive on American-made electricity, regardless of the source, rather than remain dependent on oil which has so many geopolitical downsides. People forget that even as we have become the world's #1 oil producer, we still have to import 18% of our oil from OPEC.