From a Wall Street Journal story by Aaron Zitner headlined “Why Tribalism Took Over Our Politics”:

Ahead of his arrest on Thursday in Georgia, Donald Trump repeatedly told his supporters about the legal peril he faced from charges of election interference. But the danger wasn’t his alone, he said. “In the end, they’re not coming after me. They’re coming after you,” he told a campaign rally.

It was the latest example of the Republican former president employing a potent driver of America’s partisan divide: group identity. Decades of social science research show that our need for collective belonging is forceful enough to reshape how we view facts and affect our voting decisions. When our group is threatened, we rise to its defense.