Mother Jones
That conservatives respond much more rapidly to threatening and aversive stimuli (for instance, images of "a very large spider on the face of a frightened person, a dazed individual with a bloody face, and an open wound with maggots in it," as one of their papers put it).
In other words, the conservative ideology, and especially one of its major facets—centered on a strong military, tough law enforcement, resistance to immigration, widespread availability of guns—would seem well tailored for an underlying, threat-oriented biology.