The facts are the facts, Dick. There certainly was, and is, a provable conspiracy on the right to discredit science. You can witness it daily on Fox news, Breitbart, listen to Rush Limbaugh, or just the words of Donald Trump, who claims that climate change is a Chinese plot.
As for stupidity, it's certainly that and cognitive dissonance on the part of the deniers. And they are on the right of the political spectrum invariably.