No: they’ve campaigned for years on behalf of their fossil fuel industry donors. The major oil and coal companies started a multi-decade push when the climate science debate was settled around 1980, with an end goal of protecting profits for as long as possible. The Republican Party has been trying to protect those donors but never had such strong backing to just ignore the scientists and EPA rule-making process before.
They still don't have strong backing to do this, they just don't have anyone to stop them.