Donald Trump has promised not only to be the voice of the American people, but also to take decisive, immediate action. As president, he has said he would move fast to destroy the Islamic State, scrap bad trade deals, build that wall, "stop the gangs and the violence," and "stop the drugs from pouring into our communities." He would "immediately suspend immigration" from countries where terrorism is rampant. He might even defy treaty obligations and decline to aid NATO allies.

The Republican nominee has led some to conclude that he intends a sweeping expansion of presidential authority. His rhetoric implies a muscular, almost unitary, presidency that would be at least as expansive as what historian Arthur Schlesinger jnr famously dubbed the "imperial presidency" – his critique of Richard Nixon's abuse of power in the era of Watergate and Vietnam.