I have answered my question, much like President Reagan answered national questions during his candidacy. "If it came to that, I would look at ALL my options."
The problem is this: If your best friend is wrong, do you stand up for your friend or do you stand up for what is right?
At first, when thinking about this, I thought it would depend on the situation. I thought it would matter what the "wrong" was. But then I got thinking deeper, and in reality, I would always stand up for what's right. I wouldn't tell my friend to hit the road, but I wouldn't join them either. I would try to get them to see the right way, and if that didn't work I would move on and let it go. I will never ever leave a friend over them doing something wrong (to a point), but I wouldn't stand up for them doing bad things either.
That is my final answer.