Much of the science denial dirty work was conducted for the tobacco and fossil fuel industries by free market think tanks that argued government regulations to exaggerated environmental problems were a slippery slope to communism. Think tank economists played an instrumental part by claiming that neoliberal policies like deregulation and privatization would solve environmental crises.
Free market think tanks and their members teamed up with seemingly respectable scientists to conflate political opinions with scientific facts. Science deniers derided people who exposed the tobacco and fossil fuel industries as Marxian, emotional, and unscientific.
This story roughly repeats itself when we look at trophy hunting support.