Partisan factionalism has grown more severe recently, with Republicans and Democrats increasingly huddling in exclusive camps. Compared to decades past, people are more likely to be displeased if their children marry someone from the other party, and more likely to see members of the other party as selfish.
That animosity lingers. It's not like in sports, where the importance of team preferences goes away when the subject changes, Peter Ditto, professor of psychology and social behavior, told the Orange County Register. "In politics, people see it as a moral difference,” Ditto said. "And it’s fed by the media, and by people surrounding themselves with others who think the same way."
A prominent driver? Cable television news.
"In the ’60s and ’70s, you might hear some crazy conspiracy theory during the day," Ditto said. "Then you’d come home and Walter Cronkite would tell you what the truth was. News on the three networks told you the same thing. These days, you can turn on something that supports your views."