What Trump benefits most from, I suspect, is a more limited sense that things are out of control — a feeling of anxiety about the world that pulses through your TV set or your computer screen but hasn’t yet hit your neighborhood or family or bank account directly…

If this theory is right, then in the fall campaign Trump would benefit more from economic jitters — stock market hiccups, a spike in gas prices — than he would from a sudden recession. He would benefit more from another spate of Islamic State beheadings than he would from a terrorist attack that required a major military response, and more from a continuing sense of immigration-driven instability in Europe than from, say, a real confrontation with Vladimir Putin over the Baltics.

His ideal summer and fall would feature a new form of chaos with every news cycle: Zika in the summer months, a child migration crisis when the weather cooled, a European capital in lockdown every other week. He would want to campaign amid a persistent mood of instability, anxiety and dislocation, but one that didn’t make people so anxious that they started worrying about all the obvious ways that he might make things worse.