Answer:
Cognitive dissonance.
Explanation:
Based on this scenario, Sam is experiencing cognitive dissonance. Cognitive dissonance describes Sam's feelings regarding Joann. He really likes her but he is not sure to be with her in a long-term relationship, because there is a conflict between two aspects of his feelings for her and his political ideas that are so different. People try to be consistent, and when what they believe to be true is in danger they feel cognitive dissonance, which will be tried to be reduced.