Members of Congress may not come to the floor armed with pistols as they did in the days leading up to the Civil War, but their words are as toxic as any time since then. And we are — in many ways — a more divided nation than any time since then.
In interviews with political leaders, media analysts, and people in communities around the country, ABC News found what appears to be a new phenomenon: the polarization is feeding on itself. It's not just politicians, business or religious leaders, liberals or conservatives -- or the media: It's each of us. And it's alarming.
Bill Bishop, a reporter for the Austin-American Statesman newspaper in Texas, conducted a three-year investigation into America's divide. Bishop and statistician Bob Cushing reached back over the last 14 presidential election cycles and counted Republican and Democratic votes in all 3,100 American counties.
The research yielded some startling information. "There's a steady trend line from '76 to 2004 of the country becoming, pulling apart, becoming more politically segregated. We began to see this pattern that we eventually end up calling "The Big Sort," said Bishop.
Montclair, N.J., is one of the many communities across the country that illustrates "the big sort" that Bishop and Cushing observed. A generation ago the community's vote was split 50-50 Democrat - Republican. But the 2004 election was a blowout: 78 percent for John Kerry.
In Essex County where Montclair is situated, the margin of victory has steadily widened in every presidential election since 1976. It's happening across the country. In 2004, the overwhelming majority of counties were decided by margins of 20 percent or more. The number of Americans living in these landslide counties has doubled over the last 30 years. Today, half of all Americans are living in polarized communities.
And to the political scientists who say this notion that we're divided more divided than ever is just an absolute myth, Bishop says: "I would say spend some time in Lubbock, Texas and then spend some time in Cambridge, Massachusetts. You have to look at the street level. You have to look at where people live. It's not states. States are the wrong way to look at how people live. People live in communities. It's at that community level that people are becoming more segregated."
Bishop says part of it is just a natural part of social interactions. "Given a choice, people will choose to read, be among, watch, live with, worship with, vote with, people who are like themselves," he said.
In "State Of the Union" ABC News conducts two experiments that illustrate the impact of "the big sort." In the first, Cass Sunstein, a University of Chicago law professor, conducts a remarkable experiment for ABC News that demonstrates that like-minded people are pushed to more and more extreme positions when they group together. It has profound and troubling implications for the country. In the second experiment, University of Pennsylvania professor Diana Mutz demonstrates the impact of so-called "shout TV," which is the media manifestation of "the big sort."