Did you just call him Biff?

I agree...it didn't appear that he was attacking Cheney's daughter or his family. The problem is that there is an unspoken rule about not talking about an opponent's family/children. That's where he stepped in it. The issue is still out in the mainstream, but it still doesn't come off well to be bringing it up for personal gain. Cheney took it well and then proceeded to deflate the issue. However, I'm sure he didn't appreciate his daughter being brought up on national TV.