No, it’s not.
That’s silly.
People of vastly different political persuasions mingle at important events daily. Means nothing other than that the position one holds entitles one to mingle.
Much as we abhor the reality, Barry Whozit is POTUS. He gets to go where he wants, when he wants. To fail to include him as a guest would have been a serious breach of etiquette.
I, for one, have always admired the character and class of the Bush family.
It would be better for all if 0 found something better to do that day, but inviting him was the proper thing to do.