Yphtach Lelkes of the Annenberg School for Communication said that while it’s hard to disentangle ideology from partisanship when looking at political polarization, the larger pattern appears to be that “ideology driving partisanship only seems to be occurring among those that are most aware of politics, while partisanship driving ideology seems to be happening among everyone.”
https://www.nytimes.com/2019/11/06/opinion/is-politics-a-war-of-ideas-or-of-us-against-them.html The New York Times