You believe this because you are biased and it fits your internal narrative that Republican voters are ignorant science bashers. This is baseless and divorced from reality.
http://www.scientificamerican.com/article/many-more-republicans-now-believe-in-climate-change/
A whopping 47 of Republican voters think a gas tax is a good idea!
I don't have numbers, but I am very curious what % of Republican congressman/governors believe in climate change. It's definitely not 0, but they know damn well if they start talking about it they'll lose some of their funding.