The growth of “partyism” and the decline of the antiwar movement

In a recent op ed, Harvard law professor Cass Sunstein points out that “partyism” – prejudice against supporters of the opposing political party – is on the rise in America:

If you are a Democrat, would you marry a Republican? Would you be upset if your sister did?

Researchers have long asked such questions about race, and have found that along important dimensions, racial prejudice is decreasing. At the same time, party prejudice in the U.S. has jumped, infecting not only politics but also decisions about dating, marriage and hiring. By some measures, “partyism” now exceeds racial prejudice — which helps explain the intensity of some midterm election campaigns.

In 1960, 5 percent of Republicans and 4 percent of Democrats said that they would feel “displeased” if their son or daughter married outside their political party. By 2010, those numbers had reached 49 percent and 33 percent. Republicans have been found to like Democrats less than they like people on welfare or gays and lesbians. Democrats dislike Republicans more than they dislike big business.

Increasingly, we assume that supporters of the rival political party are not just misguided about political issues, but also untrustworthy or malevolent people in general. Some of this hostility is due to “rational irrationality,” the tendency of people to make poorly reasoned knee-jerk judgments about political issues. It is closely related to the broader problem of rational political ignorance, which results in an electorate that often ignores the complexities of political issues, and tends to assume that those who disagree with their views must be evil, selfish, or stupid.