I'd like to thank everybody who commented on the last post. After much (MUCH) soul searching the decision has been made.
I will not be going to HR with the bullying issue. Believe me, I was all prepared. I even have the HR number saved to my phone. I got it today. I knew exactly what I was going to say. I was that close.
But then I got talking to the boss. The director of the department. Someone I like and respect on both a personal and professional level. He said something that indicated he is not having an easy time in his position. And as much as I want to stop the bullying of my friend, the stress and harassment that it would place on my boss would be too much. I know he will cop some of the blame, even though it would be very ill deserved.
I cannot take a problem from one person, multiply it, and dump it on someone undeserving of it. I absolutely cannot do it. So I won't. I will hold my tongue and provide support for my friend as she needs it. I will fight the asshole supervisor as is necessary. And I know that when I go, my current supervisor will do the same for her.
I am still job hunting for her though.