This makes huge sense to me.
Imagine, if you will, that you're alone in a house. A really weird noise happens. You immediately get a cold sweat and worry that something bad is happening. You have instant, negative ideation that highlights the worst case. Nobody hears that noise and thinks, "That is a weird mouse." The alarm is coming from your brain's early warning system, the amygdala. It's job is to inspire defensive reaction to events and does so by adding worrisome ideas to your thoughts.
This is, obviously, almost metaphorical in its simplicity but, it captures the high level consequence of the amygdala's contribution to your life.
So, now imagine a person being faced with a really weird noise in the form of an idea that doesn't fit with their preconceptions (just as the weird house noise doesn't fit with your expectations of quiet or gentle creaking at most). If that person has an enlarged amygdala that is more active, those discordant ideas result in an amygdala contribution and that contribution is alarming ideation.
When you say to a conservative 'abortion', it's disagreement with their already settled view that it is bad gives their amygdala reason to engage. It induces a defensive feeling of being attacked and adds horrible elements to their ideation. Liberals think, saved lives of young, used to be pregnant girls. Conservatives think, immoral whores doing whatever they want. Liberal think, tens of thousands of children who will not grow up unwanted. Conservatives think, dead babies everywhere. Etc.
In addition to the alarming ideation, the defense against attack aspect (useful if a saber tooth tiger is a real possibility, not so much if it's a fellow citizen who disagrees) prevents evaluation of the other ideas. One does not rationalize a threat. One fights it. One's preconceptions are there to be protected. Their potential change is the essential threat being opposed.
So, liberals, due to their experience with brains dominated by the anterior cingulate cortex, are perplexed that conservatives take positions that are counterproductive to their views, fail to understand the essence. Conservatives only care about protecting their preexisting ideas. A policy to minimize abortion is completely unimportant to a person whose fundamental brain motivation is to adjust the environment so that the disapproval of abortion is brought to a level that is consistent with their internal view.
This is important as we move forward into an increasingly partisan world (research shows that political views are an increasing part of mating decisions; if brain structure is a strong contributor to political orientation, we have a population of young people who are breeding purebred partisans). There is no progress to be made addressing conservatives with reason or appeals to the practical consequence of their policies. An approach needs to be devised that appeals to their interest in protecting their world view.
In a simplistic way, what we need to do is figure a way to establish a religion that is consistent with the practicality of the world. An alternative where, say, a national deficit is not seen as violating every precept of self-reliance and integrity, but is, instead, seen as, say, a garden of eden gathering of resources.
That's silly. But the point is that the smart, flexible minds who have made the modern world what it is, need to start to take into account the special needs of conservative minds. Just as we no longer try to teach autistic children using the same techniques as we do other kids, we need to devise new techniques for communicating with conservatives that take into account their enlarged amygdalas.