CLEVELAND—The plagiarism in Melania Trump’s speech last night at the convention here is an issue because a) it happened; b) the Trump people are insisting on denying that it happened, which makes all of them from Paul Manafort to Chris Christie literally look and sound like they’re in need of psychiatric intervention; c) because of their psychosis, this is going to be talked about for far longer than it would have been had someone just said the non-native-English-speaking Melania was relying on help from a speechwriter who did a bad thing and is being fired, and; d) because it’s funny.

But far more important than all these is the very real possibility that the party’s nominee for president is now sitting around in a hotel suite brooding over the injustice being done to his wife, and what this is going to do to his cast of mind during the most important week of his life.