No, seriously. Remember Republicans? Sober men in suits, pipes, who'd nod thoughtfully over their latest tract on market-driven fiscal conservatism while grinding out the numbers on rocket science. Remember those serious-looking 1950's-1960's science guys in the movies -- Republican to a one.Doctor Science at ObWi gives some history:
They were the grown-ups. They were the realists. Sure they were a bummer, maaaaan, but on the way to La Revolution you need somebody to remember where you parked the car. I was never one (nor a Democrat, really, more an agnostic libertarian big on the social contract, but we don't have a party ...), but I genuinely liked them.
I think the first shift of scientists to the political left happened around April 22, 1970 -- the first Earth Day. After that, as I finished high school and went on to college, when I said I was studying "ecology" people made immediate, forceful assumptions (one way or the other) about my political views. I remember going to a panel discussion in the mid 70s about science and politics, science and religion, where the speakers agreed that "science is not politically on the right or left" -- and I know they were wrong, because I was an ecologist and that was a political label more than a scientific one, at that time.As a hard science major, I witnessed a bit of the inside of practicing science. Though Reed College is famously liberal, the science professors are quite a bit more conservative than, say, the sociology department. As far as their actual policy views, there was fairly wide divergence, on issues from drug policy reform to universal health care. Yet they universally loathed the Republican party. I remember my intro physics professor, the legendary David Griffiths, during his lecture on gravity, stopped in the middle to give a brief aside. "Now, George Bush thinks that we should give time to alternative theories of things," he said. "Instead of Newton's Law, you could have a theory of intelligent falling, where God is pushing down on things. Sometimes he pushes up on things, like hot-air balloons. Of course, this has the disadvantage of making no testable predictions."
My memory of the 70s and 80s is that Republican Party was *not* particularly anti-evolution at the time. There were discussions and debates about "Evolution and the Bible" and such, but they didn't have a particularly partisan character yet.
What I recall being much more significant were environmental issues. Although the Clean Water Act and Endangered Species Act were passed under Nixon, by the time the Reagan administration rolled into town the Republicans were pretty strongly on the side of pollution and extinction. Many of you are probably too young to remember Reagan's Secretary of the Interior, James Watt, but that Wikipedia article covers the high points. Basically, he was completely on the side of extractive industries (including forestry and mega-agriculture). He justified it with Christianism: God wants man to have "dominion" over the earth, and besides, Jesus was coming back any day now.
...Basically -- because even the short version is getting to be too long -- I think that in the 80s the Republican powers saw even the hardest of hard scientists, the physicists and geologists and NASA, take positions that impeded the core Republican value of Making Money. Then, once they stopped worrying about what a bunch of eggheads thought, they could turn up the music playing to a Christianist audience and be against evolution and the wrong sort of medical research. But the underlying drive, IMHO, was Republican resistance to the kind of planetary systems concerns that we currently lump under "climate change".
It's a similar phenomenon to what has happened to Latinos, I suspect. Both they and scientists may not be hardcore Democrats, but they can recognize when the other party is out for their blood. It does create an atmosphere where Republicans and their ideas are deeply uncool in the scientific community, but for my money the actual actions of Republican leaders has far more effect. Not a single GOP Senate candidate supported action on climate change in 2010. I think Kevin Drum has it right:
Roughly speaking, though, this doesn't seem like such a hard question to me. The more time you spend practicing science, the more time you're going to spend discovering that conservatives hold scientific views that you find preposterous. Sure, liberals have PETA and the odd vaccination fetishist, but really, it's no contest. In the Democratic Party those are just fringe views. Even the anti-GM food folks don't amount to much. The modern Republican Party, by contrast, panders endlessly to the scientific yahooism of its base. What would be amazing is if much more than 6% of the scientific community identified with the Republican Party.