Plagiarism, as every student knows, is bad form. Campuses throw out undergraduates caught cribbing lines. But that's not the way it works in Donald Trump's world. His wife Melania is now best known for pinching some of Michelle Obama's fine words, plundering an eight-year-old speech about honesty and integrity. When Joe Biden, another American in our orbit this week, lifted chunks of an address by British Labour leader Neil Kinnock, the fallout cost Biden any prospect of securing the Democratic presidential nomination in 1988.

In a hamfisted attempt to bury the row over Mrs Trump's Republican national convention speech, party chiefs blamed Hillary Clinton, suggested the Cleveland address was "93 per cent different" from Mrs Obama's Democratic national convention speech, and cited similar sentiments made by Twilight Sparkle, a character in the 1990s cartoon, My Little Pony.

The candidate himself boasted in a tweet that "Melania's speech got more coverage than any in the history of politics especially if you believe that all press is good press."

He may have a point. The $2190 white dress Melania wore sold out within hours of her appearance in Ohio. What's more, she got loads of coverage comparing her - speechmaking aside that is - to the current First Lady. As Melania might say: "Copy that!"