As policy, that is dubious. But it is a powerful way for Mr. Trump to present himself as someone who will treat outsiders with suspicion and ruthlessly pursue economic gains. It is a message wrapped in foreign policy but meant to tap into more domestic concerns.
Colin Dueck, a George Mason University professor, wrote in a recent paperthat Mr. Trump’s worldview demands and offers “a sort of Fortress America, or perhaps a gigantic gated community, separated from transnational dangers of all kinds by a series of walls.”
To voters “feeling displaced by long-term trends toward cultural and economic globalization,” Professor Dueck wrote, Mr. Trump’s policies promise “security, separation, and reassertion of control.”