Well...yes actually. His life’s mission is to demonize and disparage his political enemies. He buys his own BS. So when he encounters his enemies in real life and discovers that they aren’t the ogres that he (and his ilk) has invented it must be disconcerting.
Fortunately (for him) his bigotry shines through.
Not only that, but Sarah’s pleasant demeanor is written off as a statistical anomaly. She was having a bad hair day and so happened to be nice that particular afternoon.