We've known Elon Musk was on his way out for several weeks, but yesterday he added the final straw - he said he was going to cut any political spending right down. This is the final end of his political adventure, because it was only his potentially unlimited amounts of cash that gave him leverage over the GOP, and that kept him useful to the Trump team regardless of his personal unpopularity with the public. If that's being ruled out for the future, it gives you some idea of how wounded he is with the experience, and how much he realises it has damaged his business interests. So what does it mean - and what are the implications for Trump and the GOP? Let's discuss.