Donald Trump’s public discourse has been characterized by making ad hominem attacks aimed at branding and delegitimizing critics and opponents, exaggerating threats or offering inappropriate reassurance, blurring the distinction between fact and fiction, stoking cultural divisions and racial and ethnic tensions, and challenging the rule of law. This rhetoric was both consistent with his pre-presidential expressions and a clear deviation from the norms of the presidency. Rather than being an asset for the president, his public discourse has diminished his ability to govern. His rhetoric has not aided him in expanding his supportive coalition. Incivility has not proven useful in attracting those not predisposed to support him, and he has not been able to brand policies effectively. Nor has he convinced most people to distrust his critics, including the media, and he has not persuaded them with either his exaggerations or minimizing of threats. His prevaricating has not won him additional adherents. Instead, the public finds him untrustworthy and not someone to whom they should defer. His public discourse and his playing to his base has brought him low and highly polarized approval ratings. Most Americans considered his rhetoric to be divisive and polarizing. In the end, Trump’s rhetoric has made it even more difficult to govern effectively. Equally important, there is reason to conclude that Trump’s discourse has been deleterious for American democracy. His rhetoric has encouraged incivility in public discourse, accelerated the use of disinformation, legitimized the expression of prejudice and increasing the salience of cultural divisions and racial and ethnic tensions, and undermined democratic accountability. Although most people reject both the tone and substance of the president’s rhetoric, many Republicans do not. Especially for his co-partisans, he has distorted the public’s knowledge about politics and policy, warped their understanding of policy challenges, and chipped away at respect for the rule of law.