Daniel Sarewitz cites a poll done in 2009 showing that only 6% of scientists identify themselves as Republican. Daniel sees this as an imbalance to be compared to the relative lack of women, Latinos, and African-Americans in scientific fields. This is interesting because he seems to imply that Republicans are under-represented because they are discriminated against. But there is no political discrimination in science. Scientists are judged on their data, their publications, and the quality of their investigations, and none of those involve disclosing political affiliation. He mentions briefly the possibility that Republican thinking is incompatible with scientific thinking, but dismisses it without further justification.
But really, that is the best explanation. Republicans hate science because the truth doesn't fit their paradigm. Scientists are not Republicans because science is aboutfacts, evidence, and analytic thought. Republicans are about manipulating behavior with emotion. The corporate puppet masters have armies of advertising geniuses creating images and generating mob appeal. No wonder scientists don't identify with Republicans, and Republicans hate science.