The paper doesn't help to answer: Why now? The model it proposes would have produced high polarization any time, but polarization is much higher now than 40 yea

The paper doesn't help to answer: Why now? The model it proposes would have produced high polarization any time, but polarization is much higher now than 40 years ago... If the model could help us analyze the dynamics of polarization it would be helpful. As a static analysis it is just a fairly obvious application of cognitive dissonance.