They explain the economic, demographic, and cultural circumstances that cause this condition to break through and demonstrate its distinguishing policy preferences. Not only do the authors define the US as a Nativist Nation historically, they also show how it has profoundly affected contemporary politics.
Specifically, they look at the primary elections in 2015–2016, during which Donal Trump tapped into a wellspring of nativist sentiment and found a receptive audience thanks to bold rhetoric.