The media have written his political obituary more than once. And each time they do, he comes back stronger than ever.

The phenomenon that is Donald Trump rolled through Virginia last week, picking up 17 more Republican delegates on his march to that party’s presidential nomination. From a punch line for late-night comics, he has emerged as a serious contender with an ever-more realistic path to the White House.

Roadblocks continue to be thrown in his way (for the most part by his fellow Republicans), and, more often than not, he just puts down his head and plows on straight through them. He has taken on TV reporters and political pundits, belittled his primary opponents in language more suited for a schoolyard, been soundly repudiated by his party’s 2008 and 2012 presidential candidates, and even gotten into a war of words with the Pope—and, in each and every case, he emerges not only unscathed but buoyed by the experience.

Along the way, he has generated enough f...