The government knows it's real, these are generally well-educated people who went to decent schools. But, I would challenge that most right-wing voters know whether it is real. Where I live in rural America the vast majority are pro-fossil fuel, anti-EV. EVs are seen as "gay" or "feminine" by the folks out here. So the choice to use fossil fuels might just be some performative machismo, allowing their pick-ups to output black smoke, make a loud noise and look "tough."
Those are the majority of the Republican voters at this stage. To make them happy you do things like spend millions to tear up infrastructure which challenges their worldview. This should result in increased votes for the current administration at the mid-terms. So even if climate change is a real and current threat, you need to say it isn't to get re-elected.
> So the choice to use fossil fuels might just be some performative machismo, allowing their pick-ups to output black smoke, make a loud noise and look "tough."
Might be linked to petrol cars being cheaper to buy for the same amount of car? That seems like an easier explanation. There is a masculine element in that men want to be seen to own big things to show off, but I doubt it has anything to do with liking black smoke. If they wanted loud noises they'd go a motorbike or get an obnoxious horn.
I don't believe they do any of this for votes. I think somebody within the administration has a personal grudge against science, especially anything related to climate change.