The authors are political science professors at Stony Brook.

Their point: The biggest divide isn’t by party.

The biggest divided is by involvement in politics.

The most vocal voices from social media, who are amplified by the mainstream media, come from a relatively small group.

Echoing what Dannagal Young had to say in “Wrong: How Media, Politics, and Identity Drive our Appetite for Misinformation, the authors talk about two sets of relatively small groups of hyper-engaged partisans.

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