NEW YORK— Donald Trump skipped breakfast one recent morning, blow-dried his hair in his Trump Tower penthouse and headed out to his personal Boeing 757 jet, dubbed “Trump Force One” since he emerged as the Republican presidential front-runner.

Seated in his plane’s living room, with its pearlwood and 24-carat gold trim, Mr. Trump worked alone, watching the big-screen TV and reading the day’s political news, mostly about him, with no binders of policy positions or talking points in sight. Upon landing, he waded alone into a throbbing mob desperate for his autograph at a packed Nashville rally.

It all fit the rule for staffers scrawled on a white board at campaign headquarters: “Let Trump Be Trump.”

The 69-year-old billionaire has soared to the top of the Republican field flying solo — a man and his plane, propelled forward by a gust of free media attention and virtually devoid of the staff, position papers, opposition researchers and ad budgets of modern campaigns. Now, though, with the time for summer flings ending and more serious voter examination just ahead, the Trump effort has reached an inflection point, at which he must decide whether he can continue to prosper as this kind of one-man show or whether the time for that is running out.

Read the article “The One-Man Roadshow of Donald Trump” on wsj.com.