Don't try to force them and don't even bring up discussions if they are not going to be mutually accepted. I have fought (not argued, but fought) just about everybody in my life regarding these issues. What can I say, lots of energy and nerves wasted and nothing came of it. Do I regret it? No, it's been pretty cool.
Is it the normal way to do things? Nope. But you need a lot of (painful) experience to learn that.
So, basically, just be calm and enjoy yourself as they go to hell with smiles on their faces...
Just to make sure. The above is a joke! Someone just told me that they felt that "be calm and enjoy yourself as they go to hell with smile on their faces" is a bit harsh. Sorry, I don't mean that literally. Of course, you are not going to passionately enjoy yourself when others are having trouble, but it's as if it's your only option, it doesn't make a difference anyway since they simply don't want to hear you. There's a funny irony, but it's definitely not a happy situation.