This website looks at a possible correlation between an increase in populism and an increase in the popularity of populist ideas through the use of Google Trends data and three articles which explain different parts of this idea.
Source 1
This source shows the increase in the popularity of populism in Europe and the United States through the increase in the percentage supporting England leaving the European Union, which is a typically populist idea.
This source shows how the increase in the popularity of populist ideas has allowed the president to reduce the budget of Enviromental Protection Agency and also reduce the amount of foreign aid that the United States provides with little repercussions.
This source shows how a sizeable percentage of respondants believe that climate change is a hoax despite the evidence that it is real.