EPA has had coal fired power plants in its sights for a while. Anyone who can remember what air pollution was like in the 1970s can understand why coal fired equipment has a bad reputation. (It is similar to the reason why Americans dislike diesel - it is based on the experience of history.) However, just look at the gains that have been made.
Most everyone can agree that we need to continue to improve and continue to reduce emissions. This only makes sense as our technologies improve. But, there is always a question of how far can you go before there are serious ramifications to an industry and then a downstream result toward the ultimate consumer. This is just the question that is currently being faced in power generation. I believe we are at the stage where we need to consider the available options and understand the consequences of increased regulation. We also have to look at the balance of resources - i.e. money, time, impacts, etc.
This is why I believe that you are now seeing states like West Virginia, Alabama, Alaska, Kentucky, Ohio, Oklahoma, South Carolina, and Wyoming beginning to join forces with industry to address issues with regulatory change.
See - the story from The Hill