We hope we won't have to learn who the real Donald J. Trump might be. Not that we find much to like about his Republican opponents, with whom we disagree sharply on issues that include climate change, environmental protection, healthcare and reproductive rights. In fact, on issues where it's possible to discern where Trump stands, his views are more moderate at times than those of his principal GOP rivals. And in their zeal to slow Trump's momentum, some have begun sinking to the Donald's level as a campaigner, slinging personal insults (at times vulgar ones) instead of focusing on the problems with his record and his campaign. Nevertheless, those candidates are more rational, knowledgeable, understandable and predictable — all of which are necessary (albeit not sufficient) qualities in the Oval Office. Trump's blustery temperament and authoritarian notion of the presidency are unique in the field and uniquely disqualifying.