Actually Carol none of the sites you refer to prove anything.
The first merely states that the State of Indiana was siding with the owners of a power plant against EPA regulations which is not surprising since the executive and legislative branches are solidly Republican and have this tendency anyway.
The second is a story about how interest groups and two states are challenging EPA regulations. You seemed to miss the part where sixteen states and NYC have intervened on behalf of the EPA because they don't want their air fouled by power plants in states seeking laxer regulation.
The third is a website for the right wing Southeastern Legal Foundation and again offers no proof of anything except that right wingers are in the pockets of big coal and don't care that these industries effect the lives of the rest of us by spewing mercury a known neurotoxin into the air and into our drinking water and a variety of toxic heavy metals that spew into the air and leach into the water supply from coal ash.