It is also the Kavanaugh vote, and the planning has been going on for months. I say it is more important than a wedding. The wedding can go on without him for one. They could also postpone the vows and just have it at a Justice of the Peace if they want him there.
If this really is an issue, he and possibly his daughter sound incredibly selfish. I can’t even imagine going there and having a good time knowing that you were holding up the country on this pivotal moment.
I don’t know which I would chose. Family is second only to God. Country comes next. Can a compromise or an accommodation be reached? I see your point of view. I also see the point of wanting to be the one to walk your daughter down the aisle on the most important day of her life and give her away. I can’t think that is selfish.