Look, the reality is that trying to detect motive, or some grand strategy, with Donald Trump is a fool's errand. The Donald is usually living proof of Occam's razor, that the best explanation is usually the simplest one. The guy had a terrible week in which he got hammered on the Russia scandal, then tossed and turned all night in his plush Mar-a-Lago bedroom, got up before dawn, turned on Fox News and scrolled through Breitbart News -- and took out all his frustrations on one of his favorite targets, a kind of Twitter blast from the past. The idea that it might be more than a little improper for the sitting president to accuse his predecessor of lawbreaking -- especially with no proof -- never crossed his mind.