I recently received an offer to join another university (in the US). I have not told my new university this, but one of the main reasons I want to leave my current university is because of another member of the faculty (let's call him "Joe").
Joe and I were in the same lab as PhD students and quarreled a lot. Later, we ended up on the faculty of the same university. I have moved on from these quarrels, but Joe continues to hold a grudge. Over the years I have tried to ignore him, but he continues to go out of his way to make my life miserable.
I'm leaving to be rid of Joe. However, my new university wants to hire more faculty in my research field, and Joe was suggested as a possible target for recruitment. They are prepared to make their next recruit a very attractive offer, so Joe may accept.
I haven't yet signed my offer, and I am not interested in it unless I am assured that Joe will not come to my new university. I can think of two ways to make a case against Joe to my new chair.
The diva approach
I directly tell the chair that I won't come unless they agree not to hire Joe. After their considerable time investment into recruiting me, they may agree to seal the deal.
The obvious downside is that this approach makes me sound immature, gripey, and dramatic to my new chair.
The good citizen approach
I make the case that Joe is bad for the department.
One major downside is that Joe did not have issues with many faculty at my current university. If my new chair tries to vet my claim with one of his contacts at my current university, my story may not hold up. Also, this approach won't provide an assurance unless I make it about me (e.g., "Joe is bad for your university, and I can't join a department with someone like him in it"), which still makes me sound like a diva.
Can anyone suggest a way for me to keep Joe out of my new university while minimizing the damage to my own reputation?