LiveScience reports on a study, "Both Democrats and Republicans Adept at Ignoring Facts." A study found that, whether Democrat or Republican, those who have strong beliefs do not listen to facts that contradict their position.
The study points to a total lack of reason in political decision-making.
Also,
The brain imaging revealed a consistent pattern. Both Republicans and Democrats consistently denied obvious contradictions for their own candidate but detected contradictions in the opposing candidate.
"The result is that partisan beliefs are calcified, and the person can learn very little from new data," Westen said.
These findings are likely true not only of politics but of any emotionally charged subject or simply of any subject that one takes for granted. These findings also explain why it is so difficult for students in composition courses to tackle topics, such as abortion or religion, if they hold strong opinions about them. I wonder how students (or anyone) can be led to use reason in emotionally charged topics. Should we just avoid such topics? Or find ways to de-emotionalize them and re-reasonize them?