When arguing, spend most of your time finding middle ground.
When people are asked to consider the other side of a topic about which they are fiercely one-sided, they typically come away even more entrenched in the position they already have. Instead of much more effective technique and getting them to be see the others point of view is to have them discuss the complexity of the issues. This gets them seeing the other side while retaining their identity, and gives them the Psychological Safety to consider alternative viewpoints. Make “That’s Right” - Your Negotiation Goal.
If we don’t understand someone we cannot have a eureka moment while imagining their perspective.