I'm not sure where it started, but several books and people refer to the no-asshole rule. This rule essentially says that no matter what, you shouldn't have any assholes on the team. At first, I'm like "exactly!".
As I think about it more, why does this have to be a rule? Shouldn't it be common sense?
It has to be a rule because for years we tolerated them. For years we believed that results were the only thing that mattered. In other words, the attitude of the manager was "sure, he is bad, but he gets things done, so what can I do?"
That is short-term thinking with long-term problems. Once you tolerate it, good people see the benefit in acting bad. Or worse, good people decide to leave.
I had this situation. I had a great performer who was well liked, but he was constantly trying to get away with things others couldn't. For years before he got on my team his actions were tolerated. Others saw that. Fortunately, his antics rarely impacted the team, but sometimes they did. Eventually, I had to make the call and I told the VP that he could move him to another area if he wanted, but he wasn't going to be on my team.
Use the rule, but make it so we never need the rule in the future.