In reality, the perception of one side being more supportive of science is simply that science media is overwhelmingly partisan and has little interest in even a pretense of journalistic standards. Criticizing Republicans sells books and it sells pageviews, but so do articles about Nibiru and the Mayan end of the world. That doesn't make them true.
The fact is that creating an 'anti-science' political party was an entirely subjective, wholly fabricated metric - 30% of Democrats and 39% of Republicans deny evolution, for example, so which side became anti-science? The right. Why is 39% a problem but not 30%? If you can answer that, you have a successful career as a progressive science blogger ahead. Meanwhile, a far more disturbing gap exists regarding vaccines and food, two issues that, unlike evolution teaching (sorry, biologists) are really national issues. It is annoying if some crank teacher in an obscure school district doesn't teach biology properly, but not a health or safety crisis the way food and vaccines are. Ditto for global warming - the idea that those two are the only anti-science positions that get discussed show that the fix is in.
In a guest post on Real Clear Politics, Dr. Alex Berezow and yours truly take down the silliness:
California Democrats have de facto allied themselves with some of the biggest anti-science quacks in America. Among Prop 37’s most fervent supporters are peddlers of alternative medicine, anti-vaccine groups, and even one crank who claims that genetically modified food causes autism.53 out of 55 signatories on the anti-science GMO warning label push at the federal level are Democrats, and 1 of the 55 is instead a Socialist Democrat, so even more Democrat than Democrats. You won't get that kind of support against global warming or evolution on the right side of the aisle.
This anti-science mentality is not a recent development. The Democratic Party has long made common cause with prominent people who thought vaccines caused autism, two in particular who stand out among the rest.
Will the partisan framing stop today? No, like with racism or anything else negative in culture, a lot of entrenched people have to fade away before science journalism stops being an unregistered PAC for one party. But the science audience is doing its part to hurry it along; while the audience for science is huge, mainstream media is cutting science departments because no one wants to read science there - they don't trust media any more. Blogs ranting about Republicans and Religion are now the go-to destinations for anti-science people who need some confirmation bias. Everyone else reads Science 2.0 (we hope).
Are Democrats Really the "Pro-Science" Party? by Alex Berezow and Hank Campbell, Real Clear Politics