THE BURNED OVER DISTRICT

When Hillary Clinton speaks to the public about foreign policy she is referring to real policies past and future concerning real interactions with other nations. When Donald Trump talks about foreign policy he is just selling another bag of kibble to the Trumpoons and yelling, "Dinner Time".

As Mr. Trump and his Democratic opponent, Hillary Clinton, meet on Wednesday for their final debate, in which foreign policy is slated to be a main topic, a look at his wholesale reframing of this set of issues reveals much about Mr. Trump’s improbable rise.

Studies show that most voters rank foreign issues low on their list of concerns, but they do listen and use those issues as a window through which they judge candidates’ values and ideology.

Mr. Trump has exploited this dynamic, offering ideas that experts consider unworkable, but that tap into some voters’ desire for a strong-handed leader. Foreign policy, some research suggests, provided an ideal medium for this message.

Typically, candidates cannot reach the national stage without first proving their fitness to certain institutions that care deeply about foreign policy: the news media that vets them, the parties that provide them with crucial support, the policy makers they will need once in office.

Because foreign policy is so complex and most voters do not follow its particulars as closely as they do domestic issues, those institutions play an outsize role in shaping the bounds of acceptable debate.

But Mr. Trump, a celebrity who largely self-financed his primary campaign, was able to bypass this process, hacking the politics of foreign policy to his considerable advantage — and in ways that could outlast his candidacy.

All candidates wrap their policy agendas in simpler values, such as strength or inclusiveness, or stories of heroes and villains, Professor Saunders said, “as a way of crafting a narrative that voters who don’t follow the details can grab on to.”

That is especially true for foreign policy, she said, because it is so complex.

Mr. Trump seems to have reversed this process, beginning with the narrative and values he wishes to convey, then designing policies to maximize his message’s effect.

Because foreign policy requires difficult trade-offs, conventional candidates are limited in how emotionally appealing they can make their plans while keeping them workable. They also need to appease the hard-nosed policy experts or party officials those candidates rely on to get elected — and, eventually, to govern. But Mr. Trump was under no such constraints.

The result: Mr. Trump’s foreign policy is not a foreign policy at all, but rather a vessel for reaching voters on a purely ideological level.

A foreign policy based on its appeal to the masses and any connection with reality is just a happy and unintended accident. And it hooks the rubes every time.