Up until 1998, Republicans and Democrats were equally likely to believe that climate change resulted from human activity and was already having an impact.
And then it became political. A decade later, Democrats were almost twice as likely to believe that climate change was real.
As it turns out, Democrats aren't smarter or better educated than Republicans. Nor are Republicans more scientifically inclined than Democrats. Randomly select a member from either party and you're about as likely to get someone who couldn't explain their way out of a rain storm. Or for that matter, about as likely to give you a cogent argument based on science. (Note that actual scientific experts, however, are not divided on climate change. I'm making a point about the average layman, the voter who can swing an election.)
Once climate change became political, though, it became a matter of identity, of being in the club. If you have lots of Republican friends, it becomes increasingly awkward to argue for climate change. By contrast, if you hang out with Democrats, it is hard to argue that climate change is not such a big deal.
I think its true that - outside of scientists, philosophers, and prophets - very people seek truth at the expense of alienating friends and family. Most folks would rather hang out with actual people than be alone with ideas or facts. It's peer pressure that seems as likely to shape our beliefs as an objective look at the facts. And now the argument is not scientific: it's an attack on you and your group. To change your belief might mean alienating you from your peer group. That's tough to ask of anyone, unless your peer group is fellow scientists, philosophers, and prophets.
[Last note: the Gallup numbers since 2008 haven't changed much. It's now 79% probable that a Democrat will belief in climate change. Republicans are unchanged at 41%.]