How did this happen?  America has changed. We did not see it coming.  And looking back, we don’t know how it happened.  Not so long ago, people spoke respectfully of the President, even if they had not voted for him. Not so long ago, attitudes toward guns, immigrants, abortion, Genesis did not divide us so deeply.  That world now seems lost, and we wonder what world is coming. I want to explore this polarization in this essay.


I don’t use these terms in this essay, but they each are useful in naming some of the concepts in today’s polarization.

  • American exceptionalism:  the notion that the U.S. is superior to other countries. Many who believe in exceptionalism also believe that the U.S. has a unique mission to change the world, and make people free everywhere.1
  • Foreign Interventionism:  the notion that the government should intervene in the affairs of another nation as part of its foreign policy. Such intervention may include occupation and nation-building.
  • Jingoism: Advocacy of aggressive foreign policy in the belief that threats and force will best safeguard national interests.
  • Nativism: Opposition to immigration and immigrants, often coupled with the belief that immigrants will spoil cultural values, take jobs, or lower wages.2 Nativists appear to have the most trouble with those for whom English is not their first language.
  • Protectionism: The notion that trade should be restrained through barriers such as tariffs, quotas, and regulations to ensure “fair” competition between products produced domestically and those produced overseas.
  • Traditionalism: The notion that the beliefs and traditions of the past should be maintained in the future.
  • Xenophobia: Fear of foreigners, of the unfamiliar, of change.

Tracking the Growing Polarization

Not long ago, a survey from the Pew Research Center revealed that political polarization in the United States Congress is now more extreme than since the Civil War. The gap between what Democrats and Republicans believe is enormous, with almost no middle ground. In the chart below, high numbers represent polarization in Congress, where party members vote along party lines. This tendency to vote along party lines appears to have been “normal” before World War I and since World War II.
Party polarization

Between 1900 and 1975, Republicans steadily grew more moderate, and are now becoming more conservative.  Between 1879 and the 1920s, Southern Democrats were more liberal than Northern Democrats, but are now more conservative. Democrats in Congress began to become more liberal in the 1950s, and moved about .2 units on the scale during that interval.  Republicans didn’t begin becoming more conservative for another 25 years — in 1975.3

NOMINATE polarization


Psychological Forces: Birds of a feather…

It is difficult to maintain a polarized position when you have frequent encounters with other views.  As a result, many at the extremes seek to cut off their exposure to such views. This need to be surrounded by others that are like-minded appears stronger in conservatives than liberals4:

  • 15% of Democrats and 17% of Republicans would be unhappy welcoming someone from the other party into their family.
  • Among consistent conservatives, 63% say that most of their close friends share their views. Among consistent liberals, 49% say this.  For those with mixed ideological values, only 25% feel that their close friends must share their views. The more negative our views of the other side, the more actively we seek like-minded associates.
  • People on the right and left also are more likely to say it is important to them to live in a place where most people share their political views, though again, that desire is more widespread on the right (50%) than on the left (35%).
  • Far more liberals than conservatives think it is important that a community have racial and ethnic diversity (76% vs. 20%). At the same time, conservatives are more likely than liberals to attach importance to living in a place where many people share their religious faith (57% vs. 17% of liberals).

Over the past 15 years, the Internet, email, and cable TV have all helped in the creation of an infinite number of special interest groups. Everyone is now able to surround themselves with opinions that match their own, and thus strengthen their own. Once this selective exposure allows us to conclude that others agree with us, we are comforted, and our opinions become strengthened.

The Internet Changed Us.

Before the Internet, we all had to go to the same few sources for our information. Today, Google can deliver a list of 87 million links to papers that prove the earth is flat.

Internet Events
 1978 The first SPAM was sent to all users of the ARPANET from DEC, plugging a demo of some equipment.5
 1988 The first SPAM USENET post.5 The first known electronic chain letter.7
 1991 “The Web” launches with a paper from CERN
 1993 The word “SPAM” is first used to describe mass unsolicited commercial e-mail.5
 1996 Hotmail launches
 1997 is registered as a domain name.
 1998 Google gets funding, files for incorporation, sets up workspace, and hires its first employee.
 2002 Google launches AdWords, in which ads displayed are selected based on the keyword searched.
 2002 SPAM goes ballistic, with the highest volume per year to date.
 2003 Google announces AdSense, a content-targeted ad service for content publishers. First anti-SPAM legislation.
 2007 Google introduces Google Safe Browsing to help protect users from malicious web content by blocking access to such pages.
 2008 Chrome released for Microsoft Windows.
 2010 Google Instant launches, showing you search results as you type the query.

Most search engines and social networks (e.g., Google, Facebook) now use computer algorithms as filters, personalizing web content based on a user’s search history, location, and previous clicking patterns, creating more polarized access to information9. This method of personalizing web content results in filter bubbles that remove unrelated information and opposing views.10

Cable TV Changed Us Too

As television offerings have increased, there has been growth in the number of polarized news media options. As a result, viewers can find political programming that is one-sided — their side. Such polarized programming can offer self-confirmation for ideology.11


We all receive unsolicited e-mail. For most of us, e-mail with messages we agree with is likely to be retained and read.  For the rest, the mail is deleted, or marked as SPAM, so that we never hear from that source again.  The result is that a typical in box is dominated by messages we agree with.


Gerrymandering creates voting districts that are more uniform in their views, and thus more polarized. Polarized districts can give rise to polarized elected officials. Political scientists are not agreed on the magnitude of this effect, but it seems likely that redistricting plays some role in polarization.12

Growing Income Inequality in the U.S.

For the past 50 years, the gap between rich and poor in America has grown.

During the 30 years since 1983, upper income families have seen their wealth double. During that same period, those of middle-income and lower income saw their wealth rise and fall with the housing market, leaving them no better off today than they were 30 years ago.13
Polarization and Income Inequality

As may be seen in the graph below, this has been due mostly to an increase in the real income of the wealthy, while the real income for the bottom half of America hasn’t changed.14
NOMINATE polarization


Rising income inequality has been linked to political polarization15. The chart below compares the fraction of all national income claimed by the top 1% of the population, a measure of income inequality, with the degree of polarization. As Martin Sidwell as commented, “Income inequality in the USA is not on a par with other advanced economies, members of the OECD, but with Bulgaria, Iran and Uganda.”16
Polarization and Income Inequality

How does income inequality impact polarization?

  •  According to a 2013 study published in the Political Research Quarterly, elected officials tend to be more responsive to the upper income bracket and ignore lower income groups.
  • One change in elections is the increased power of the few to influence outcomes. … Citizens United… When a few wealthy individuals choose to spend heavily, voting is skewed to favor those who favor their causes. And so the wealthy can improve the chances that those elected will support policies which favor the wealthy. example: Bush and tax cuts
  • Anger from falling buying power for those who would be in manufacturing jobs. They may claim the economy is bad, but it is their economy that is bad. The beginning of the growing gulf between rich and poor in America might have begun with NAFTA and other forces that shifted manufacturing jobs overseas.

Strengthening the Gap

On measure after measure – whether primary voting, writing letters to officials, volunteering for or donating to a campaign – the most politically polarized are more actively involved in politics, amplifying the voices that are the least willing to see the parties meet each other halfway.17

Special language helps people see sides. For instance, liberals never refer to a “liberal agenda” or to the papers they read as being the “media elite”

Correlates of Polarization


While the country is full of liberal idiots and conservative rocket scientists, conservatives may have lower IQs, on average, than liberals. Several studies briefly cited here suggest this. The connection is puzzling, and may be complicated. Perhaps a lower cognitive capacity makes people more attracted to simplifying ideologies that require less effort in thinking.


There is evidence that liberals have more education than conservatives. The Pew Research Center has found18 that:

  • In 2014, of those with an education of high school or less, 37% are Republican or lean Republican, and 47% are Democrat or lean Democrat — a 10 point gap.
  • Of those with some post-graduate experience, 36% are Republican or lean Republican, and 56% are Democrat or lean Democrat — a 20 point gap.

In another analysis, the percentage of voters in a state that have a bachelor’s degree is compared with the percentage that identify themselves as a liberal. The graph below shows that where voters are more likely to have Bachelor’s degrees, the state is likely to have relatively more liberals.

Another hint comes from surveys of approval of liberal and conservative presidents. With Barack Obama and Bill Clinton, those with post graduate education have shown higher approval ratings than those with high school level education. But with George W. Bush, those with postgraduate education had lower approval ratings than those with a high school education.19

Less educated whites have been shifting to the Republican party since 2008. The GOP now holds a 54 percent to 37 percent advantage among non-college whites, who were split about evenly four years ago. The partisanship of white college graduates, by contrast, has not changed, the analysis found.20

The reason that educational attainment correlates with liberal/conservative views might somehow be related to the finding that college faculty are more liberal than entering freshmen, and perhaps with each passing year of education, the liberal professors draw the less liberal students closer to their views. In 2014, college professors were roughly 30% more likely to identify as liberal than were college freshmen. This gap has increased from 1990, when faculty were only 16% more likely to consider themselves liberal.21

There are several plausible explanations for why liberals have more education:

  • Liberal families are more open to learning, more comfortable with education.
  • Intelligent students likely do better in school, and stay longer. We saw above that IQ correlates with liberalness. So if those completing many years of education have higher IQs than others, it may be an artifact of attrition that education correlates with liberalness.
  • Students are influenced by their faculty, and each year of contact with liberal faculty is likely to increase the correspondence in views between faculty and students.
  • Education is expensive, and liberal families may be better able to afford it.

Of course, faculty have had more education by liberal faculty, perhaps accounting for some of this gap.

Effects of Polarization

Polarization has many consequences. Here are a few.

Partisan animosity

Partisan animosity has increased substantially since 1994. In each party, the share with a highly negative view of the opposing party has more than doubled since 1994. Most of these intense partisans believe the opposing party’s policies “are so misguided that they threaten the nation’s well-being.”22
It is important to note that  the majority do not have uniformly conservative or liberal views. Most do not see either party as a threat to the nation. And more believe their representatives in government should meet halfway to resolve contentious disputes rather than hold out for more of what they want.23


Those with the most extreme views are increasingly the most vocal, as well.  In recent years, the political center has become increasingly disengaged.24 Many of those in the center remain on the edges of the political playing field, relatively distant and disengaged, while the most ideologically oriented and politically rancorous Americans make their voices heard through greater participation in every stage of the political process.25 The graphs below show that the extremists are most likely to vote and to contribute to a political candidate.

Shift Toward Extremism

Since 1994, there has been a steady shift of Republicans to the right, and Democrats to the left.  In 1994, about half of those surveyed took a roughly equal number of liberal and conservative positions. In 2014, this is down to 39%26.

Comment from Steven Stang

Hello David-

I was happy to stumble on your writings last night and hadn’t realized that you had still been adding to them. ‘Polarization’ is timely and reflects a very dangerous trend well underway.

I had already given much thought to the ‘college as a liberal citadel’ circumstance. Recently I ‘reentered college’. Thanks to EDX, I first attended Harvard. There I studied philosophy. Boring and predictable- a good mental exercise with little connecting it to the real world. There were troubling items that gave me pause- Aristotle like Jefferson was a slaveholder- doesn’t that serve to invalidate his teachings about liberty and justice? Beyond a few items like that, it was isolated academia. Then I went to Cornell. I took a course on ‘American Capitalism’. Surely this would redeem my faith in America. It is our system, our gift to the world, and what a cornucopia it has produced! Except that I quickly learned that the systems didn’t produce the wealth, theft did. Theft of labor (slaves) and theft of resources (stole all the lands from the indigenous owners) Wow….Then the United States developed the worlds security markets!!! We started securitizing assets and trading them in New York. That’s my kind of stuff. Trade commodities, stocks, etc. But wait- what was the first security created by these brilliant and soon to be wealthy financiers in New York? _ pools of slaves- grouped by gender, age, skills into large pools that could be traded on newly formed exchanges. Like-minded people in Europe loved the idea and soon these securitized slave pools exceeded the value of all other assets in America-  COMBINED. The south was then, of course, way wealthier than the north because of this. The United States was  the worlds first slave society, soon followed by the only other one, Brazil. A slave society differs from a society that has slaves in that slaves never are freed, their heirs are slaves too and they outnumber their masters. The fact that they outnumber their masters requires a body of law which is unique for them that protects the masters from them. Violence was expressly allowed. One was free to kill a slave without any consequences UNLESS HE WAS SECURITIZED AND PART OF AN INVESTMENT POOL!!!! It got far more discouraging, the more I learned, and so I went to NYU! There I took several courses offered by Eric Fromer, a reknowned civil war scholar. Yes, it was true, what I had learned at Cornell. In fact it was worse. The North didn’t fight the South because of slavery, they fought it because of the dissoluiton of the Union. In fact many Northern regiments withdrew when Lincoln issued the Emancipation Proclamation which freed  not all but only Southern slaves. He was hoping they would join Northern armies- Maryland got to keep theirs!! He didn’t want to piss of his Northern supporters. New York wasn’t happy either. Their security pool values plunged and there were riots in New York and actual physical violence.

The South has romanticized the causes of the war. They say it is about federal authority. That is not true. Prior to the war, there was no federal authority. There was no federal taxing, only a modest government, no Army, etc. The President was a slaveholder from Mississippi at the start of the war (James Buchanan) and the Supreme Court was totally owned by the South (Dred Scot, etc). The Fugitive Slave Act had been promulgated by the south and shoved down the throats of the North making it a Federal crime not to apprehend slaves or suspected slaves and return them to the South. The notion of the war being about ‘federalism’ is pure fantasy and 180 degrees off the mark. I could go on and on but what is the point? I am already way off track and late for work!

Back to the polarization issue:  When kids go off to college, they don’t know this stuff. They learn it and say- wow! Have I been getting fed bullshit? First it was Santa, then it was the Easter Bunny, then it was the myth of American Greatness….. what’s next? Jesus Christ himself??? Oh well, in four years I can go back to my happy place, amass wealth like a good New Yorker, and get comfortable… if only the liberal media (owned by Fox and Rupert Murdoch) wouldn’t keep intruding on that happy place!

That is how college kids turn liberal. Unfortunately their professors have no way to leave the truth behind and it becomes a lifelong condition.

I need to start my day…. you have a good one. I have solved my dilemma by transferring to Kyoto University to study primates and tsunamis.

Show 26 footnotes

  1.  Source.
  2.  Source.
  3. Political polarization in the U.S. House. Created by Chris Hare, and published here.
  4.  Political Polarization in the American Public
  5.  source
  6.  source
  7.  source
  8.  source
  9. Rushkoff, D. (2010). Program or be programmed: Ten commands for a digital age. Berkeley, CA: Soft Skull Press.
  10.  Pariser, E. (2011). The filter bubble: What the internet is hiding from you. New York, NY: The Penguin Press.
  11.  Mann, Thomas E.; Ornstein, Norman J. (2012). “It’s Even Worse Than It Looks: How the American constitutional system collided with the new politics of extremism”Basic BooksISBN 978-0-465-03133-7.  Hetherington, Marc J. (17 February 2009). “Review Article: Putting Polarization in Perspective”. British Journal of Political Science39 (02): 413. doi:10.1017/S0007123408000501. Hollander, B. A. (1 March 2008). “Tuning Out or Tuning Elsewhere? Partisanship, Polarization, and Media Migration from 1998 to 2006” (PDF). Journalism & Mass Communication Quarterly 85 (1): 23–40. doi:10.1177/107769900808500103.
  12. Polarization (politics)
  13.  The American Middle Class Is Losing Ground
  14.  The Rich and the Rest of Us in the United States
  15. Josh Harkinson (September 13, 2013). Chart: Washington Gridlock Linked to Income InequalityMother Jones. Retrieved September 16, 2013. 
  16. Martin Sidwell. Economic Consequences of Inequality
  17.  It’s Been 150 Years Since the U.S. Was This Politically Polarized 
  18.  Party Identification Trends, 1992-2014 
  19.  White Gender Gap in Obama Approval Widens With Education 
  20.  Is education level tied to voting tendencies? 
  21.  Liberal Professors Outnumber Conservative Faculty 5 to 1 
  22.  Political Polarization in the American Public 
  23.  Political Polarization in the American Public 
  24.  It’s Been 150 Years Since the U.S. Was This Politically Polarized
  25.  Political Polarization in the American Public
  26.  Political Polarization in the American Public Pew Research Center.