June 12, 2014

The polarized Congress of today has its roots in the 1970s

You don’t have to look hard to see evidence of political polarization — just watch cable news, listen to talk radio or follow social-media debates. Indeed, a new Pew Research Center report finds that Americans are more ideologically polarized today than they’ve been in at least two decades. Their representatives in Congress are divided too, and have been pulling apart since the days of M*A*S*H and Billy Beer.

With Democrats and Republicans more ideologically separated than ever before, compromises have become scarcer and more difficult to achieve, contributing to the current Congress’ inability to get much of consequence done. But going beyond anecdotal evidence to examine congressional polarization more rigorously can be tricky.

Fortunately, political scientists Keith Poole and Howard Rosenthal have developed a widely accepted metric, DW-NOMINATE, that places every senator and representative on the same set of ideological scales. Using their data, it’s clear that the congressional parties, after decades of relatively little polarization, began pulling apart in the mid-1970s. Today, they say, “Congress is now more polarized than at any time since the end of Reconstruction.”

The researchers aggregated roll call votes to locate each member of Congress, from 1789 to the present day, on a two-dimensional grid. One dimension represents the traditional liberal-conservative spectrum; the second picks up regional issue differences, such as the split between Northern and Southern Democrats over civil rights in the 1950s and 1960s. As Poole and Rosenthal note, those formerly significant regional distinctions have declined in importance — or, more precisely, merged into the overall liberal-conservative divide: “Voting in Congress is now almost purely one-dimensional — [political ideology] accounts for about 93 percent of roll call voting choices in the 113th House and Senate.” So we used just the ideological dimension in our analysis. 

We took the vote scores for every senator and representative in five Congresses, one in each of the past five decades, and ordered them from most liberal (scores of -1 to 0) to most conservative (0 to +1). Then we sorted them by party to see how much overlap — if any — there was between Democrats and Republicans (for simplicity, we excluded the handful of independents).

In 1973-74, there was in fact substantial overlap. In the House, 240 members scored in between the most conservative Democrat (John Rarick of Louisiana) and the most liberal Republican (Charles Whalen of Ohio); 29 senators scored between New Jersey’s Clifford Case (most liberal Republican) and James Allen of Alabama (most conservative Democrat).

A decade later, though, that had already begun to change. By 1983-84, only 10 senators and 66 representatives (except for Rep. Larry McDonald (D-Ga.), who scored more conservative than every single Republican) fell between their chambers’ most liberal Republican and most conservative Democrat. By 1993-94, the overlap between the most conservative Democrat and the most liberal Republican had fallen to nine House members and three senators. By 2011-12 there was no overlap at all in either chamber.

What’s happened? In large part, the disappearance of moderate-to-liberal Republicans (mainly in the Northeast) and conservative Democrats (primarily in the South). Since the 1970s, the congressional parties have sorted themselves both ideologically and geographically. The combined House delegation of the six New England states, for instance, went from 15 Democrats and 10 Republicans in 1973-74 to 20 Democrats and two Republicans in 2011-12. In the South the combined House delegation essentially switched positions: from 91 Democrats and 42 Republicans in 1973-74 to 107 Republicans and 47 Democrats in 2011-12.

Political scientists debate whether polarization in Congress preceded or followed polarization among the wider public, and our data (which begins in 1994) won’t resolve that. One thing is clear, though: When a polarized Congress represents a polarized public, not much gets done legislatively. Through the end of May, the current Congress had enacted 89 pieces of substantive legislation (based on the methodology we’ve employed in prior Fact Tank posts) since it opened in January 2013. A decade ago, at the equivalent point in its term, Congress had enacted almost twice as many substantive laws.

Historically, compromise has been key to getting legislation passed. But polarized senators and representatives — reluctant to compromise with the other side to start with — won’t get much pressure from the partisans back in their home states. According to our study, while 56% of Americans say they prefer politicians who are willing to compromise, in practice both across-the-board conservatives and across-the-board liberals say the end result of compromise should be that their side gets more of what it wants.

Topics: Congress, U.S. Political Parties, Political Attitudes and Values

  1. Photo of Drew DeSilver

    is a senior writer at Pew Research Center.


  1. J.S. Koh2 years ago

    Whole society has been polarized. By 1970s, we had a formidable virtual enemy, communism. When we were getting in Pax Americana era, American government and people are changed to be less generous, and the population of middle class is getting thiner. If we compare the polarization to the income distribution chart, I believe that there is pretty good similarity. Society is changing by it’s economic condition.

  2. J.D. Shatz3 years ago

    I think that the senators’ backgrounds may also play a role here. In the 1970s, a majority of the senators had served in the Second World War, and others served in Korea. That commonality in their background could allow senators not only to share their experiences, but also to find a shared value in public service that could transcend partisanship.

  3. GreyGhost3 years ago

    QUOTE: ” Congress’ inability to get much of consequence done. ” Why is this a a problem.? If you look at congress in the last 100 years, them doing nothing only benefits the country. The serious issues they can always come together on. Declarations of war, etc. The less they do, the better off we are. We just need to manage the other branches of the government not to overstep their bounds to compensate or try to implement ideological government largess. To do nothing, especially after an event hyped in the media, is a good thing. The government doesn’t solve problems. It never has, in fact I would bet the empirical data would show that they indeed hinder and exacerbate problems.

  4. Creed Pogue3 years ago

    If you look at the range between -0.5 and .05 as the “middle” and -0.6 to -1.0 as “liberal” and 0.6 to 1.0 as “conservative” then there is a major “red shift” for both parties. In the 93rd Congress, there were two Democratic senators and less than 17 congresspeople who scored “below” -0.6 and no one scored “below” -0.8. There was only one Republican senator who scored “above” 0.6.

    Twenty years later, there were still only two Democratic senators who scored “below” -0.5 but -0.6 was the “lowest” score. Last Congress, NO Democratic senators scored “below” -0.5 while eleven Republican senators scored “above” 0.5. In the House, only one GOP member scored below 0.3 while over forty were higher than 0.8.

  5. Bob S3 years ago

    I would love to see a more detailed explanation of this…

    “We took the vote scores for every senator and representative in five Congresses, one in each of the past five decades, and ordered them from most liberal (scores of -1 to 0) to most conservative (0 to +1). Then we sorted them by party to see how much overlap — if any — there was between Democrats and Republicans (for simplicity, we excluded the handful of independents).”

    What issues were deemed conservative or liberal and how were they scaled? I’d also love to see how socialist Bernie Sanders rated on your system.

    As it is, you seem to be saying that Rs have become far more conservative than the Ds have become liberal, but you don’t show how that conclusion was arrived at. It’s hard to trust a rating system that is not only highly subjective, but is not explained in detail.

  6. Frank T. Manheim3 years ago

    Many researchers have dug into Congressional polarization, though none with the solidity and impact of the Pew Trust’s studies. What’s new is the observation that a large central segment of the U.S. public has a diversity of views and is not ideologically polarized (a conclusion documented statistically in the 2005 book by Morris Fiorina) – but is also politically passive. It’s the radicalized Democratic and Republican wings that are the activist and run the show.

    I’d like to point out that I came to virtually identical conclusions as did the Pew researchers in my book of 2009*, though I did not back up the critical “activism” aspect with detail and statistics as Pew did.

    Where my research went beyond Pew’s esteemed study was to the systematic tracing of the conflict between environmentalists and industry to its root causes in turbulent events in the 1960s, culminating in the Santa Barbara offshore oil spill of January 1969. I also examined outcomes and historical background in detail. My results were published by a respected academic publisher, Springer which I learned explains why my book has not gotten wider attention. U.S. scholarly publications are, for the most part, produced in a virtual apartheid system. Scholarly products rarely get to the attention of media or the public. This is a critical problem in its own right for American society which I also explore in the book.

    A compounding factor is that my candid treatment of the above and other issues apparently made the book too sensitive to review in ordinary disciplinary media – even though its multiple discoveries would normally merit special attention. Previously unknown facts were revealed by interviews with framers and other key people involved with our pioneering environmental laws.

    Herewith a very brief summary of relevant history. The sense of environmental crisis and loss of confidence in federal regulators triggered by the Santa Barbara spill led a bipartisan group of activists in the Senate to push through revolutionary new environmental laws (the CAA and CWA). They were both approved unanimously in the Senate (!). These laws set a precedent for a series of later, rigorous environmental laws in the 1970s.

    The pathbreaking laws were brilliantly written for political effectiveness. They made rapid inroads on pollution and other environmental problems. But they also incorporated fundamental flaws: 1) Their operational detail in effect transferred primary leadership for formulating policy in complex scientific-social areas from professional agencies to Congress – which has no inherent scientific or professional expertise, or capability of monitoring and managing programs it initiates. 2) Dispute resolution was given to federal courts, which likewise have no built-in professional expertise – they declare winners and losers; 3) The above transformations politicized environmental decisionmaking; 4) The new laws deliberately inhibited enforcing agencies from taking policy initiatives or discretion without Congressional approval (i.e. new or amended laws). The structure and complexly interlockng nature of laws have made the laws nearly impervious to adaptation to new science, needs, and conditions.With rare exceptions environmental policy has thus been frozen in models responding to conditions 35 or more years ago.The antagonism and they aroused led to conflict over environmental policy, which widened in the early 1980s into partisan polarization.

    In contrast, since the late 1980s, European nations have moved toward decentralizing policy and with an emphasis on cooperation rather than conflict. So, we went from a being an international leader in environmental policy in the early 1970s to the below, startling ratings for the U.S. in environmental performance since 2006. The ratings are based on the Yale-Columbia University Consortium’s rankings in EPI Index for 173 nations:

    YEAR 2006 2008 2010 2012 2014

    U.S. rank 39 26 61 49 33

    The top ten ranks are dominated by advanced European nations.
    I’d welcome further communication.

    Cordially Frank T. Manheim

    *See my web site: policy.gmu.edu/manheim

  7. Marvin Sands3 years ago

    It seems to me that Republicans have moved further to the right and as a consequence are not in any way willing to adjust or look for compromise. If our country is going to make any progress within this divisional split, both parties are going to have to find ways to compromise and accept some defeats with some wins. We cannot remain so ideologically bent and not willing to give ground for the benefit of our country.

    In addition, money seems to be driving the machinery — way to much money. Not the people and what is best for Americans. The people have lost their voice and the influence of money has taken over.

  8. jerry garcia3 years ago

    My son is a lobbyist. His experience convinces him that party and ideology play insignificant roles in congressional and legislative deliberations. Go figure.

  9. Evil Overlord3 years ago

    The data presented seem to suggest that it’s been mostly the Republicans pulling to the right, not the Democrats pulling left. The data may be open to question, though since it seems to me that both Democrats and Republicans have moved right; the Republicans have just moved further and faster.

  10. Ralph. Kolderup3 years ago

    Perhaps,with the inability to cooperate….We will have less govt!

    I hope so.

  11. Terry Rosson3 years ago

    I believe one of the biggest contributors to polarization is doing away with the Fairness Doctrine. Around 1986, I think. Now anyone can blurt out any “facts” they want and not be challenged with the real stuff.

    We need the Fairness Doctrine back, on Fox, on MSNBC (as if this was the equal of Fox in driving any kind of polarization). And reporters need to do their real job–weigh in with undisputed facts to counter someone who’s just making it up.

    This also applies to Letters to the Editor. I remember editors used to correct misstatements of fact. Even in automotive magazines! We need this fact checking back–right at the moment fake facts are stated.

    1. Mr Aragon+USA3 years ago

      We Need to protect The Public interest “ The devolution of the American press began in 1986 when Ronald Reagan abolished the Fairness Doctrine.

      We had a law in this country that we passed in 1928 that said that the air waves belong to the public. The broadcasters can be licensed to use them, but only if they use them to promote the public interest, to inform the public and advance democracy. That’s why we have the 6 o’clock news. They didn’t want it. The broadcasters didn’t want that because the news departments were chronic money losers.

      But they were forced to put on the news at 6:00 and even today you hear news on the music radio stations and that’s an artifact of the Fairness Doctrine. They said, if you’re using the broadcast air waves, you have to do that…

      They no longer have an obligation to serve the public interest. Their only obligation is to their shareholders. They serve that obligation not by informing us, telling us the things we need to understand to make rational decisions in a democracy, but rather by entertaining us…

      We know we’re the best entertained, the least informed, people on the face of the world. They got rid of their investigative reporters. 85 percent of them lost their jobs in the last 15 years.

      They got rid of their foreign news bureaus so the Bush and Cheney administration can say to the American people, ‘Oh, we’re gonna go into this 800-year-old fist fight in Mesopotamia and they’re gonna meet us with rose petals in the streets’ and the Americans believe them.
      The Canadians didn’t believe them because the Canadians still have a Fairness Doctrine…

      England has the same kind of rules and in Europe, but in our country, we lost those rules and, as a result, we know a lot about Britney Spears’ gradual emotional decline and we know a lot about Charlie Sheen, but we don’t know much about global warming or the fact that the Appalachian Mountains essentially no longer exist.”

      What do you think? Are we better off without this media policy or has our democracy suffered from its elimination?

  12. J Michael Antoniewicz II3 years ago

    From 2012-10-29


  13. MB3 years ago

    It is interesting to see that the ‘blues’ start pulling further to the right and then the ‘reds’. Reds voted more on liberal or center issues but blues very little on red issue or center.
    It seems like when the liberals became more radical there was a backlash as the centrists and right reacted by going further right. The Democratic party of JFK about sacrifice for the country (“Ask not…”) turned into the the “X” generation.
    So the fringes in both parties started having a greater following hence the polarization. Liberals believe in “change” , Conservatives like the status quo, hence their name conservative, don’t like major changes in their lives or society. They like change to be slow and progressive. Radical ideology has scared the conservative; as major social changes are being pushed too quickly by political agendas on the left, on the right there has been a backlash.

  14. JK3 years ago

    I think it is important not to overlook the infusion of money into our political process during the studied time period. Big money, including Corporations, wealthy individuals, and now Internet donors, have increased campaign contributions exponentially since the 70s. Lobbying has grown to the point where it is now considered an industry.

    Most of these monies are targeted at a narrow self-interest. Very few dollars are channeled toward systemic solutions, moderate causes, or healthy debate.

    Is the split representative of the true leanings of our citizens, or does it reflect the ever increasing imposition of “big money” into a supposed democratic process.

  15. Old Dragoon3 years ago

    The Religious Right is only partly responsible for the polarization that started in the ’70’s. The cultural chaos of the Vietnam era, the Left ‘s “in your face” self-righteousness and visible disdain for their opponents contributed, too. Branding Vietnam returnees as “losers” and “baby killers,” everyone who doesn’t support gay marriage as “homophobic” or everyone who doubts that climate change is a result of human activity as “ignorant” does not help the quality of political discourse.

    1. kimothyanne3 years ago

      I was against our involvement in Vietnam then, and nothing I have read since has changed my mind.
      However, anyone with half a brain did not blame the soldiers who were obligated to serve there, with the war. Although I protested the war, the people I was friends with did as well, I never actually met anyone who called the returning G.I.’s names, or accosted them in any manner. Those I knew as well as myself always felt they were victims of the same lies the rest of us were being subjected to.
      It may have happened on occasion, I do not know, but I don’t think it was a rampant behavior. At least not by those who understood “why” they were against that “war”.

      1. Joe McFeron3 years ago

        I was hitch-hiking home in my fatigues and carrying a duffel bag in Walla Walla, Washington in 1969. It was about 5 miles and I had walked half of it with nobody stopping to give me a ride. Finally, a VW bus with all the peace markings on it stopped. Jogging up to it, I was met by two bearded hippie-types and their “ladies,” hoots and snarls and one-finger salutes, the inevitable “baby killer” oath, and finally spat upon. They drove away. In a few minutes the police arrived and checked my ID. They drove me to my sister-in-law’s house where my wife was staying. One of the cops had returned from Nam the previous year. We both came home from service having no idea how much the country had changed, even as we knew we both had living in another world. I will never forget the experience, and I know I am not alone in that.

      2. Matt Campbell2 years ago

        Just before Christmas of 1969, I remember going with Mom & Dad to pick him up my Uncle Ted, A huge 6’5′ Viking and a highly decorated Green Beret (Project Delta), at Charlotte’s Douglas Airport. He was coming back from Vietnam. Whenever he was traveling he was a sharply dressed Green Beret Master Sargent. [He had been in Officer Candidate School, when he kicked a Captain’s ass for insulting his date at their graduation dance. Busted, the Green Berets came after him.]

        After the holidays, while waiting on an outbound flight to go back, Ted went into a bar in Douglas Airport to have a couple drinks. The Bartender, being a pinko commie lib hippie, started making comments about all the babies we were killing in Vietnam, trying to engage Ted in a debate. Ted told him he didn’t know what the hell he was talking about, and if he didn’t keep his mouth closed he was going to throw him though the window.

        Well, that just outraged the Bartender into full on “baby killer mode.” But, not as much as, ACTUALLY flying through the window. Fairly quickly a couple of Charlotte Policemen show up, and the Bartender demanded they arrest Ted for attacking him with no good reason. Ted told the officers exactly what happened, and the Bartender’s day just got even worse again as the Police decided Ted had shown great restraint by even bothering to give him a warning, which he loudly protested as they arrested him instead.

  16. slk3 years ago

    the difference before and after the ’70’s is the rise of liberalism/socialism/communism!!! you now have socialist congressmen, where as in the fifties everyone thought mccarthy was a lunatic for thinking socialism/communism was infiltrating our country!!! before the seventies, the only time you heard “spread the wealth” was in communist nations!!! now congressmen run on that platform!!! so of course, there’s a divide, and it grows every minute, like our debt clock skyrockets(7 million a minute)!!!

  17. Rob Carty3 years ago

    Very interesting data. It would be fascinating still to compare this data to historical gerrymandering and see if there is any correlation.

    1. mark3 years ago

      That is a very good idea. It makes me wonder if cities and counties have been so gerrymandered that we have “locked ourselves” into this disparity.

  18. John3 years ago

    Some of us saw this happening in the 70s & 80s as the religious right got heavily involved in Republican politics. The “their way or the highway” approach to government is the undoing of the party. They can’t elect a candidate without we moderates joining in the general election, and they won’t nominate anyone we can live with as presidential candidates.
    As was the case with the majority leader this week, a lot of Republican moderates just stayed home and drank coffee.

    1. Evil Overlord3 years ago

      I do think that increased pressure from religious/values conservatives has been a factor. There’s been an increased desire to de-secularize government – to insist that government actors promote a Christian view. That has led to conflict. The right (and the country) might have been better off simply promoting their views and values without dragging government in.

  19. Enzo Porfavorny3 years ago

    These graphs do not show causation. So, there’s an additional story to be told. I agree with Bob Collins – I’d like to see each Congress charted since 1789, and compare it to events in our Nation’s history. At least a correlation might be drawn. Otherwise, this simply indicates that our Senators and Representatives are at odds with each other more strongly now than since the 93rd Congress. What a surprise. Or should that be What – a surprise??

    1. John Baltierra3 years ago

      You have a good notion but the political labels have changed through the generations, as well as the political ideologies. Graphs that would satisfy your curiosity–and mine–would be too complex for general consumption. Nevertheless, that would be interesting.

  20. Daniel I Hohenstein3 years ago

    Have you also taken into account the Gerrymandering of the districts. This practically compels the congress to cast votes with sole intent of winning both primary’s and general elections. One or two changes need to be made: either invalidate all the re districting done in the last 50 years and pass legislation invoking term limits on both houses. These positions were not intended to be a career choice. So much time and expense and influence peddling is a result of this aspect of our democratic experiment and now more than ever it has an overwhelming negitive effect on the governance of this country.

    1. slk3 years ago

      one six year term for potus!!! congress – two terms, and if you want to “campaign” for a 2nd term, you must step down, so someone is always working for the people!!! and finally, no special retirement package (full congress salary, plus 50% more if married, over 200 g’s a year), live on social security, and fix it, so our childrens children, will have something!!! bet most people don’t know about their retirements!!!

    2. Eden millecchia3 years ago

      Well said!

    3. John Baltierra3 years ago

      Yes, you highlight a salient aspect of US politics. However, that’s only one layer of the complexity that’s affected today’s political demography. Realize that the US population has doubled since the Vietnam Era. Also, the tremendous jobs-related diaspora of the Sixties as technological, industrial, and military deployments became active. We had gerrymandering of requisite adjustments for population migration–and growth. Yes, the US has been a “happening place”. It’s not entirely unexpected that our politics would evolve in multiple ways.

  21. Howard3 years ago

    Over the last two decades the percentage of purely political political roll call votes have increased. Take the votes on the Affordable Care Act alone. The votes were designed to strategically align the members of Congress to appease the more conservative wing of the Republican party.

    Have you adjusted to reflect voting on radicalized issues that have no hope of passing. This would seem to push the ideological center way out of whack. I think if you could filter these votes out you would see a few Republicans leaning more to the center and few more Democrats conservative.

    1. slk3 years ago

      radical, like hr4646 – 1% tax on any money transfers!!! taking out, putting into an account, from one account to another!!!

  22. Bob Collins3 years ago

    Any chance we can see the split from other times in our history? How does this particular polarization differ from other periods?

    1. John Baltierra3 years ago

      Amen. It seems truncated to only use the Seventies as their starting point. When LBJ “lost the South”, in the Sixties, is an interesting period of political shift. Of course, earlier contrasts and comparisons would be interesting as well. However, it’s entirely likely that PRC is totally aware of such possibilities, in more compatible circumstances.