What effect did Donald Trump have within and beyond America? This article assesses the policy impact of the President using the new layered framework for understanding the impact of political leaders, which considers their effect on the connected layers of societal structures, political institutions and policy. Firstly, the article extends the framework with a new typology of change. Secondly, it draws from the empirical articles in this volume to map his effects under the new typology and the layered approach. Trump is found to have largely acted as an accelerant for already existing causal processes in society, rather than providing a radical break with past politics in many areas. By undermining democratic institutions and encouraging hyper-partisanship within political institutions, for example, he was strengthening prevailing causal forces rather than constructing new forces. However, there were some more substantial effects such as the reversal of progress towards racial equality. In the layer of policy, he crucially failed to slow or reverse destructive pressures on the economy and public health or even fulfil major campaign promises on healthcare. Overall, Trump illustrates neither the strength nor weakness of the office of presidency, but instead the dangers of poor political leadership to citizens in America and beyond, especially in times of crisis.