Everyone - even me - was saying that sooner or later a huge falling out between President Trump and Elon Musk would have to happen. Just when we thought that had been avoided, suddenly it's all kicking off. The fact of the falling out, then, is as expected - but the fact that it's over a point of real substance that matters - actually, that's more surprising. It may just focus an important part of America on the issue of the national debt. And given who's involved, it will probably do so in ... colourful ways. Let's discuss.