Conservapedia:Writing for the enemy
Writing for the enemy is the process of explaining another person's point of view as clearly and fairly as you can. The intent is to satisfy the adherents and advocates of that POV that you understand their claims and arguments.
It's a great way to end an argument in real life, and it can often halt an edit war in an instant.
Note that writing for the enemy does not necessarily mean one believes the opposite of the "enemy" POV. The writer may be unsure what position he wants to take, or simply have no opinion on the matter. What matters is that you try to "walk a mile in their" shoes instead of judging them.