ABSTRACT
To call Donald Trump's election a surprise is an understatement. Most prediction models and polls are atheoretical, i.e. they are not based on a theoretical model, and their reputation and weighing are mainly based on previous predictions. If there is anything we can learn from the victory of Trump, it is that the extremely low response rate is creating major problems for polls – not just in the US – and that pollsters need to rethink their margins of error, which were established when polls had much higher response rates. There were two political science theories that received particular coverage in the run-up to the election, and which were taken to task after Trump's surprise win. The first holds that the party decides, which relates mainly to the stage of primaries, while the second argues that money decides, which applies to both stages of the presidential election.
