The inability for anything resembling reason. empathy or interaction with the "outside world" to intrude upon one's political views.
Or, if the disorder of autism is characterized by impaired social interaction and communication, and by restricted and repetitive behavior; then the term "polical autism" would refer to the lack of communication and interaction with certain types regarding political views different from their own. It refers to the inability to reach them with anything like logic, feelings, reason, etc.
Rick Perry: "Abstinence only sex-ed works"
Interviewer: "Texas is 3rd in the nation in teen pregnancies" Perry: "Abstinence works"
Interviewer: "3rd highest"
Perry: "But... abstinence works"
Me: Rick Perry, when all you can do is repeat to yourself and insist upon the same things in the face of different information or stimuli, you seem to be someone suffering from a form of political autism.