Four months before my daughter’s wedding, she told me that her uncle (my brother, “Dave”) would make her feel unsafe if he was a guest. She asked me not to invite him. My daughter is very politically progressive, as are many of her friends, and although she and Dave have always had a good relationship (I thought), he is a conservative voter and has supported candidates we all abhor. Dave has always been very nice, so my daughter’s request surprised me. I wrote Dave a very nice note, telling him that we would not be comfortable with him at the...