Ann Coulter sums it up perhaps best, writes Peggy Noonan in the WSJ. Defending Donald Trump is “like constantly having to bail out your 16-year-old son from prison.”

Seven months ago, political pundits were saying that Trump would sink himself with his outrageous comments. Yet the more outrageous he became—for example, his pejorative statements regarding John McCain and Megyn Kelly—the more his poll numbers went up. Donald has not changed, but what is hurting him now is “the aggregate—a growing pile of statements and attitudes that becomes a mood, a warning sign, a barrier,” continues Ms. Noonan.

It has all added up into a large blob of sheer dumb grossness. He is now seriously misjudging the room. The room is still America.

At the same time Mr. Trump doesn’t even seem to be trying to do the one big thing he has to do now. He is the front-runner for the nomination. At this point it is his job to keep the support he has and persuade those who don’t like him to give him a second or third look. To do that he only has to be more thoughtful, stable and mature in his approach—show he may be irrepressible and fun and surprising, even shocking, but at bottom he has within him a plausible president.

Instead, he is stuck at nutty. Rather than attempt to win over, he doubles down. In the process he shows that what occupies his mind isn’t big issues, significant questions or the position of the little guy, but subjects that are small, petty, unworthy.

Instead of reassuring potential or reluctant supporters, he has given them pause. Instead of gathering in, he is repelling. This is political malpractice on a grand scale.

Read more from Peggy Noonan here.