America needs a populist president.

Populist movements get people to the polls at home and abroad. This year’s historic midterm turnout is just one example of voters showing up to fight rhetoric they deem dangerous.

Leaders and parties that exercise dictator-like control over the governments to which they were elected pose an intense, immediate threat to democracy worldwide. Civil liberties, freedom of the press and global security are at stake.

“I mean, I voted, but why does it matter? London will never listen.” When I asked my new Scottish friend about the United Kingdom’s recent election, he responded with pure ambivalence. He truly...