I can think of situations in which you should tackle the faculty.
- When you have a legal obligation or a mandate from further up the administrative food chain. "I know you don't like it, folks, but we have to do it."
- When you have some actual power to enforce. "If we don't get cooperation with the new policy, we won't be able to fund Project X. Take your pick."
- When you have strong support from vocal and respected campus leaders. "On the recommendation of the Faculty Senate, I am instituting the following policy."
- When your position is so morally compelling that you couldn't do anything else. "I cannot in good conscience support the current policy."
It helps if you have more than one of the above.
Note, oh administrator, than I'm not claiming that this is the way things should be. It's the way things are. And if you don't recognize it, you're going to have a very hard time.