To hear his rivals tell it, he’s a neophyte charlatan unfit for the job he’s seeking. A huckster with zero lines of his resume that are relevant to the job he’s now pursuing. A gate-crashing fool who might be able to string together a few zingers, but hardly qualified to open the nuclear football with wisdom or shut down a stock market with credibility. A danger to the post-World War 2 world order, someone who would surrender to Moscow and fling almost a century of foreign-policy convention into a woodchipper, a chump who just doesn’t get it. Or maybe worse of all.