Donald Trump has unleashed on former MAGA mate Elon Musk, accusing him of being a “train wreck” and “off the rails” in a searing Truth Social post. The latest spat between the president and the richest man in the world has flared up after Musk officially fied paperwork to start his new “America Party”.

His threat this weekend to launch a third national party, based on his disappointment at President Donald Trump’s failure to eliminate the deficit, is likely to be a disaster — for him, and for Americ...