Sadly, the other side offers flaccid resistance. It is not as if they are vigorously pro-science or pro-reason - they're just not-anti. I believe a significant source of this problem is the decoupling of electability from results. It is simply understood that any candidate's promises are empty, and that they will "govern" in a way wholly inconsistent with the way they campaign. Candidates spend so much time raising money and campaigning that actual governance is an after-thought. Indeed, doing anything at all is a mistake for nearly any elected official, because it gets in the way of more empty campaign promises. That said, no matter how asinine either party behaves, changes in incumbency are fractional, rather than monumental.
What is the answer? Voters must hold candidates accountable for their promises, and most especially, moderate voters have to be active in local party politics so that primaries aren't an exercise in extremism. When a candidate doesn't deliver what they promise, or indeed does precisely the opposite - he or she must be voted out of office pronto.
And anyone who says, "Evolution is just a theory and I don't believe it," shouldn't even be allowed to run for town council or school board, much less national office. Failing to educate an entire generation of children due to insane dogmatism would be an unforgivable lapse in our responsibility to the world, and our successors on this planet.