Looking at American politics, it seems like there is a tremendous animosity between people with different political leanings. Was it always this polarized? If not, when did this trend begin and why?

*Edit: As per a comment by @jamesk, I am editing this question. These hard feelings are true all across the world. Was the world always so polarized? When or how did this begin?

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    I think you need to be more specific about just what you mean by polarization? There have always been groups at the fringes, but (at least in my personal observation), those fringes have attracted more people, and more vociferous ones, in the last few years.
    – jamesqf
    Commented Feb 8, 2021 at 5:57
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    Is this a question about US politics or world-wide?
    – lalala
    Commented Feb 8, 2021 at 12:47
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    @lalala OP edited the question to say specifically: "Was the world always so polarized?". It's asking about the world in general, though US polarization was certainly on their minds when asking
    – divibisan
    Commented Feb 8, 2021 at 17:29
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    You understand without an objective definition of "polarized", you will get little more insight than a barroom argument over who a league MVP is?
    – Hasse1987
    Commented Feb 9, 2021 at 0:41
  • You may be interested in today's book review at (the excellent blog) Astral Codex Ten, which covers just this question: astralcodexten.substack.com/p/book-review-why-were-polarized
    – dbmag9
    Commented Feb 10, 2021 at 12:41

10 Answers 10


Polarisation is not entirely new, but it’s not a constant either. Looking just at US national politics, there have been other periods of very strong polarisation (e.g. the late 19th century, following the Civil War), and other periods of comparative consensus (e.g. the mid–late 20th century, during the Cold War).

Fivethirtyeight.com has run quite a few articles on this topic, looking at various quantitative measures of polarisation through recent US history. A good recent run-down is Geoffrey Skelly’s Why a Biden blowout didn’t happen…, and more can be found under their polarization tag. Broadly, their analyses support the claim that on a historical scale, the current polarisation is not unique or extreme; but it is the most polarised that US politics has been since WWII, so within living memory for most Americans, it is new.

(Other answers give further good points which I won’t repeat, especially comparisons in a broader international and historical context.)

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    "and other periods of comparative consensus (e.g. the mid–late 20th century, during the Cold War)" -- immediately brings to mind, "We've always been at war with Eastasia."
    – TKoL
    Commented Feb 10, 2021 at 14:47
  • @TKoL: Note the word “comparative” — I’m well aware that there was still plenty of conflict. And “bipartisan consensus” would be a bit more precise for the claim I’m making. But you disagree with the claim that US politics was less polarised then, I suggest you write another answer to explain why, since no current answers are presenting that argument, as far as I can see. Commented Feb 10, 2021 at 15:27
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    No no, I'm not disagreeing at all! That's a quote from the book 1984 - the fact that a period of time when America, for example, had much less political polarization coincides with the time when we all agreed on a common enemy just perfectly coincides with that part of the book 1984, as that was used in the book implicitly to be this big lie they used to placate the masses.
    – TKoL
    Commented Feb 10, 2021 at 16:24
  • @TKoL: Ah, sorry — I misunderstood what you meant, I thought you were suggesting that I and others were misrepresenting the past. Thanks for the clarification, and yes, good parallel! Commented Feb 10, 2021 at 17:05

Personal animosity between political opponents is widespread and historic. It is particularly common in democracies.

In an oligarchical or dictatorial state, power and influence depends on your closeness to the dictator, and the dictator tends to surround himself or herself by people of the same opinion. In a democracy, people of differing views are brought together to debate, argue and in some cases this leads to personal animosity and even fights.

Examples abound, from Ancient Athens, where votes to expel (or ostracise) people reveal Athenians’ attitudes toward their fellow citizenry. Some feature nasty epithets: “Leagros Glaukonos, slanderer;” “Callixenus the traitor;” “Xanthippus, Ariphron's son, is declared to be the out-and-out winner among accursed sinners.”

Civil war politics included several fights in Congress included one in which an abolitionist Senator was nearly beaten to death for insulting and publicly mocking a pro-slavery Congressman.

There are, of course, plenty of counterexamples. Fierce political enemies who are good friends (Frank Fields and Nicholas Soames) or even marriages (John and Sally Bercow).

In America in the period 1940-1980 there was a period when the clashes were within, not between the parties. And there was the real enemy of Nazis or Communist Russia that both parties could unite against. This period may make us think that bipartisan politics is the norm. America is also unusual in that the President often requires support from at least some members of the other party to appoint his/her cabinet and get legislation passed.

The breakdown of this bipartisan politics began under Ronald Reagan (who followed an economic policy that, unlike his predecessors, didn't attempt to be centerist) and accelerated under Obama and particularly Trump. Trump's personal style is to insult and belittle his opponents. This get his supporters and opponents emotionally involved. And where emotions rule, there is little room to "see the other side" or "respectfully agree to differ".

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    Social media also played a big role in the polarisation as well.
    – nick012000
    Commented Feb 8, 2021 at 2:50
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    @nick012000 CItation needed.
    – gerrit
    Commented Feb 8, 2021 at 9:58
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    @gerrit Here's one article talking about it: phys.org/news/…
    – nick012000
    Commented Feb 8, 2021 at 10:05
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    @gerrit There is also this video by CGPGrey which explains how filter bubbles lead to unjustified anger about what is perceived as the political enemy (but is usually a straw man version of it).
    – Philipp
    Commented Feb 8, 2021 at 13:07
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    Citation needed on the bit about Reagan, too. Congress controls the vast majority of economic policy and any bill raising revenue must originate in the House, per the Constitution. The House was controlled by Democrats for the entirety of Reagan's two terms as President. Republicans had a slight Senate majority during his first 6 years and Democrats had a slightly larger one during his last 2.
    – reirab
    Commented Feb 8, 2021 at 23:33

Newt Gingrich as Speaker of the House was the watershed moment.

  • Soon after his House Speakership he managed to get the government shut down for a fairly long while.

  • His "throw the bums out" presaged the Tea Party (and Trump's rather amusing claim to "drain the swamp"). Sure, Pat Buchanan also had that kind of message (peasants are coming with pitchforks), but he was more of a wild man than a major insider.

  • It wasn't enough to campaign on policies, Newt really set out to paint the opposition as unacceptable as the opposition. And anyone within his party who was willing the compromise (you know, to actually get things done in government) as a traitor.

Quoting Wikipedia:

A number of scholars have credited Gingrich with playing a key role in undermining democratic norms in the United States, and hastening political polarization and partisan prejudice.[7][8][9][58][59][60][61][62][10][63][64][11] According to Harvard University political scientists Daniel Ziblatt and Steven Levitsky, Gingrich's speakership had a profound and lasting impact on American politics and health of American democracy. They argue that Gingrich instilled a "combative" approach in the Republican Party, where hateful language and hyper-partisanship became commonplace, and where democratic norms were abandoned. Gingrich frequently questioned the patriotism of Democrats, called them corrupt, compared them to fascists, and accused them of wanting to destroy the United States. Gingrich furthermore oversaw several major government shutdowns.[65][66][67][59]

University of Maryland political scientist Lilliana Mason uses Gingrich's instructions to Republicans to use words such as “betray, bizarre, decay, destroy, devour, greed, lie, pathetic, radical, selfish, shame, sick, steal, and traitors” about Democrats as an example of a breach in social norms and exacerbation of partisan prejudice.[7] Gingrich is a key figure in the 2017 book The Polarizers by Colgate University political scientist Sam Rosenfeld about the American political system's shift to polarization and gridlock.[8] Rosenfeld describes Gingrich as follows, "For Gingrich, responsible party principles were paramount... From the outset, he viewed the congressional minority party's role in terms akin to those found in parliamentary systems, prioritizing drawing stark programmatic contrasts over engaging the majority party as junior participants in governance."[8]

(Bit of speculation on polarization)

In the larger picture, not just the US, the world has become more polarized even as mainstream Western parties have largely converged to a center-left/center-right set of economic policies:

  • Large scale Socialist nationalizations a la Mitterand have been shown not to work. Thatcherism stopped England's gradual descent into economic irrelevance and British voters were not keen on bringing back the good old days via Corbyn. Yet, a hard Thatcher-style position, with mass privatizations and anti-union stance would surely lose modern elections.

  • Reagan-style trickle down ended up not trickling down very much but Clinton was able to run a surplus and was generally popular running a somewhat center(right) set of policies, something also done by Tony Blair.

  • Any Ayn Rand style wild dreams of Libertarian economics have remained just dreams and don't attract many voters. Balancing budgets has ceased to be a priority for most right wing parties.

  • Outside the US, policies such as public health care are now the norm across the board.

  • Even places like Sweden have gradually retrenched their tax burden and relaxed taxes on the rich. At the same time, Western economies slice of government GDP has ballooned up as the government is expected to provide many services.

  • Meanwhile, the West is under massive stress. Accustomed to centuries of dominance over the rest of the world we now are competing with them. Between globalization, automation and ever greater need for education in many jobs, many blue collar jobs that would have provided adequate living in decades past have gone. Even white collar jobs are facing outsourcing and automation. No mainstream party has found an answer (nor is it clear what it would be if it even exists).

In short, even as the substance of economic policies converged, the parties seem to have become ever more strident in denouncing each other. Dissatisfied voters, whipped up by social media and unhappy with the status quo kept by the main wings of their respective parties, have increasingly supported positions on the fringes. You can see this in France (Melanchon and LePen) or Italy (Lega and 5 Stars).

So while I agree with other answers that we have been more polarized in the past, those were also times when the main parties actually had massively divergent positions on how to run a country, unlike now.

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    While Corbyn lost in both 2017 and 2019, this 'British voters were not keen on bringing back the good old days via Corbyn' is a rather strong statement for 42% vs 40% result in 2017, an election that might have been about something other than Brexit.
    – Jontia
    Commented Feb 8, 2021 at 8:47
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    While I agree with your observation that polarization rose with Newt Gingrich's rise, I think the ultimate cause of the polarization was the end of the Cold War. There no longer was a common external enemy, so Americans turned on each other as the enemy. This created the perfect opportunity for Gingrich, Grover Norquist, Rush Limbaugh, etc. to take control of political discourse. Gingrich had the most political power of this group.
    – DrSheldon
    Commented Feb 8, 2021 at 15:53
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    @ItalianPhilosophers4Monica I don't disagree, but the actual policies of neither candidate were really on the agenda in 2019. Brexit was ultimately the only issue on the agenda and Labour's position of negotiating then asking the country to decide if it wanted the deal was deemed too complicated. And if I knew why anyone voted for the promises of a known liar I'd probably be doing a very different job.
    – Jontia
    Commented Feb 8, 2021 at 16:20
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    @ItalianPhilosophers4Monica and yet if you look up polling on the actual policies that Corbyn supported, they perform vastly better than their election results would suggest. The fact that much of the media tried their hardest to cast him as some amalgamation of Hitler and Stalin probably contributes a lot to that difference
    – llama
    Commented Feb 8, 2021 at 17:53
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    @ItalianPhilosophers4Monica for me it's the same reflex as comes up when I hear Labour can't win without Scotland. Or all the great Tory policies from 2010, which all turn out to be LibDem policies. Corbyn had some very serious flaws, but his platform especially in 2017 was popular.
    – Jontia
    Commented Feb 8, 2021 at 19:22

Quite frankly, politics has not always been this polarised. It has often been worse. A couple of examples:

  • At the time about half of the states of the US rebelled against the Union and seceded to form their own country. The reason for this was the abolitionist platform of the Republican Party at the time which threatened the economic backbone of large areas of the South: slavery-based agriculture. It bears noting that the President, whose election triggered the aforementioned events, had frequently stated he had no intention to abolish slavery and believed it outside of his rights to do so.

  • The interwar period is taught as a particularly violent period of German history. Among high-profile names, Karl Liebknecht and Rosa Luxemburg, former socialdemocratic politicians that later split off to ultimately for the Communist Party, were assassinated by Freikorps, right-wing paramilitary units often recruited from war veterans.

    Aside from these two, there were clashes between communist supporters and right-wingers all through the 1920’s and the Nazi party famously had its own paramilitary, the SA.

  • In Russia, the Russian Revolution(s) of 1917 led to a struggle between more conservative political forces and socialist ones which evolved into a civil war between the Bolsheviki and the centrist White Army. A very similar development occured in Finland where most of the city of Tampere was destroyed in the civil war of 1918.

  • In general, political assassinations form a bloody line all through history.

In the examples above I have concentrated on western countries at a time when political parties similar to present day ones existed. It should be noted that political violence is not constrained to these geographic areas nor these timescales as the James’ answer shows. Also, I have just picked out four significant raisins ignoring a multitude of other possible examples to keep the answer short.

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    In the case of Luxemburg and Liebknecht, the Freikorps were in league with Ebert (SPD) and the assassination was signed off by Noske (also SPD). So it's not (just) an example of left-right polarization, but also of left-centrist polarization.
    – tim
    Commented Feb 8, 2021 at 13:30
  • Yes, the first half of the 20th century in Europe was certainly quite extremely polarized in most countries. After the end of monarchy and WWI, Austria basically had two parties, each with their own paramilitary organisation, both of which had the declared goal of replacing democracy with something else as soon as they had the necessary majority. There was a (short but bloody) civil war and a clerical dictatorship - all that before the Nazis took over and things got even worse.
    – Hulk
    Commented Feb 8, 2021 at 16:01
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    @tim Indeed, that time was interesting and I now better understand why the KPD used Sozialfaschisten towards the SPD. Sadly, much of this was glossed over in school to spend more time devoted to the dictatorship a decade later …
    – Jan
    Commented Feb 9, 2021 at 5:21
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    The Anni di piombo in Italy is probably a good slightly more recent example of extreme political polarisation. 20 years of regular assassinations and bombings. Commented Feb 9, 2021 at 20:08

It's difficult to answer this objectively over long periods of time owing to lack of comparative instruments. If we restrict discussion to the US Congress voting record, it's probably the longest-track instrument that can be used. To get just one graph (on US House of Representatives) which goes back to the 45th Congress (1879) from a related question

enter image description here

Measurements at larger population level are stymied by lack of polls that consistently asked the same question, so only a narrower time frame can be compared, e.g.

enter image description here

Using data from the American National Election Study (ANES), the figure shows trends in average feeling for the party participants identify with (in-party) and for the opposing party (out-party). In-party feeling (green line) has remained high over the period plotted, though it has decreased slightly in recent years. Out-party feeling (purple line) has decreased dramatically, especially after 1990.We also plot affective polarization (gray line)—the difference between mean in-party feeling and mean out-party feeling—which shows a significant increase over time (Iyengar et al. 2012), mainly due to an increase in animus against the out-party. However, it is worth noting that affective polarization actually decreased between 2012 and 2016 due to decreases in feeling toward the in-party.

As you can see polarization has been increasing in the US in the past 3 decades by most measures, but at least based on Congress data, it was just as high in the 1930.

Measuring polarization for more than two parties (which relevant for many other non-US countries) is somewhat more difficult, methodologically, as there are multiple valid measures of polarization even for the same data. Again owing to data about parties being more easy to get than for the public in other countries too, the X axis in the following graph is relevant. As you can see polarization went up in some countries more than in others.

enter image description here

Again, whole population measures aren't usually available except for shorter time frames:

enter image description here

The US trend since the 1980 isn't reflected in (many) European countries up to 2010 or so. But note that this data (owing to time frame in that study) does not cover the more recent rise in the populist right in Europe.

And of course, if by "world politics" you mean relations between countries, that's more difficult to quantify, but surely the Cold War and World Wars before that were periods of higher polarization in that sense. (Someone even predicted the "end of history" as the Cold War was ending...)


The book "Why We're Polarized" by Ezra Klein takes an in-depth look at the polarization of the United States specifically. One main source of polarization identified in this book was the realignment of political parties in the 1960's around the passing of the Civil Rights Act. Up until that time, the Democratic party was composed of two main factions: Southern Dixiecrats (who were notably opposed to civil rights legislation that would improve the lot of Southern African Americans) and Northern Democrats (who cared about passing progressive legislation such as the New Deal but relied on Dixiecrats to win). This uneasy alliance:

"kept the Democratic party less liberal than it otherwise would've been, and the Republican Party congressionally weaker than it otherwise would've been, and stopped the two parties from sorting themselves around the deepest political cleavage of the age". - pg. 31

Northern Democrats broke with Southern Dixicrats and allied with some Senate Republicans to pass the Civil Rights Act (though Republican presidential nominee Barry Goldwater notably opposed the Civil Rights Act, thus cementing the identity of Democrats as the party that passed bill and Republicans as the party that opposed it.) In the fallout, Dixiecrats largely realigned themselves with Republicans following it's anti-civil rights leader Goldwater. From there, it was much easier for the parties to drift apart because ideologically, they now fell on opposite sides of the spectrum regarding race, civil rights and progressivism to a larger extent.


So far, no answers have mentioned Duverger's Law.

This states that the pressures under the plurality (first-past-the-post) voting method push toward 2-party rule. With centrists and third parties pushed to the sidelines, voters are forced to "pick a side", increasing polarization.

With the information age permitting massive, nationwide coordination throughout each of the major parties, this process has only gotten more efficient with time.

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    It should be noted that, in a two party system, the Nash equilibrium is for politicians from both parties to move toward the center because they can count on people more extreme than they are and are effectively competing for the centrist voters. The fact that this is not happening is the puzzle the OP faces. One explanation is that the deciding factor in many elections is not whether politicians have gained a larger share of the population but how well they have mobilized/energized the voters already on their side.
    – farnsy
    Commented Feb 8, 2021 at 20:19
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    A candidate will not have a chance in the general election without the backing of a major party. Parties hold primaries/caucuses to decide who the will back. Primaries select candidate toward the center of the primary voting population, not the general voting population. This process ensures that candidates running in the general election are not centrists.
    – eclipz905
    Commented Feb 8, 2021 at 20:39
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    @farnsy Bear in mind, that a 2-party system does not mean there are not only 2 parties. It means that only 2 parties have any relevance. If a party tries to move to the center, they risk losing the extreme end, and splitting the party. Combining this with the spoiler effect would mean that the (now) centrists and the upstart party would both be at a disadvantage against their established opposition.
    – eclipz905
    Commented Feb 8, 2021 at 21:15
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    @farnsy The Nash equilibrium assumes that the number of voters will remain constant, particularly at the extreme ends. In the 90s there was significant realignment in the US to "mobilising the base" rather than "competing for the center" because it became clear that it was more efficient to convince apathetic voters that were already on "your side" to vote than it was to compete for the center. It then became clearer that the more radical you could portray the other side, the easier it was to scare people into voting. Hence the current crop of fear campaigns. Mandatory voting fixes this.
    – throx
    Commented Feb 8, 2021 at 22:06
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    @throx I think that's exactly right.
    – farnsy
    Commented Feb 9, 2021 at 2:38

For most of the 20th century, the US had a strong contingent of what, for lack of a better term, I will call "reasonable people" -- not precisely centrists, but people with no great investment in any ideology, neither activists nor wishing particular harm on anyone -- and willing to stay out of their neighbors' lives as long as the neighbors stayed out of theirs.

This group moderated the two party system because if they perceived one party taking too hard of a stance, they would be entirely willing to vote for a candidate of the other party. The parties had to take some stands to distinguish themselves and attract voters, but not so many as to alienate the bulk of voters.

With the coming of cable news and the internet, this group has seemed to evaporate. The result was a feedback effect: the parties felt comfortable taking stronger stances, moving their positions further apart, which made it less likely for voters to ever consider changing sides, which led he parties to radicalize their positions yet further. News coverage of presidential elections used to talk about candidates courting the swing voters, but by 2004, "has anyone ever seen a swing voter?" was the joke of the day.

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    I don't think it's so much a matter of swing voters ceasing to exist as it is a matter of both parties running such poor candidates that swing voters dislike both of them and either hold their nose and vote for the one closest to their views (regardless of how much they may dislike their personal character,) stay home, or vote third party. For example, in the 2016 election, both candidates had strong majority unfavorable ratings for the entire election cycle.
    – reirab
    Commented Feb 8, 2021 at 23:49
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    @reirab: Much of this is (IMHO, anyway) a result of the more open, "democratic" primary system. That tends to favor the more extreme candidates, since the extremists (in any direction) are most often the ones motivated to do the grunt work of campaigning, and will actually vote in the primaries. The older "smoke filled room" method of selecting candidates at least usually produced ones moderate enough to appeal to the middle of the road voters.
    – jamesqf
    Commented Feb 9, 2021 at 4:27
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    @jamesqf On that point, I'd largely agree. Also, the more centrist voters can only vote in one primary or the other, so their votes are split, even if they're closer to each other than they are to the candidates on the extremes of each party. And then, first-past-the-post strikes again with the primaries, too, especially if it's a crowded primary like the 2016 GOP one. Many of the early states that Trump won, he did so with only around a third of the votes in those states, for example, due to the more reasonable votes being split many ways between the other candidates.
    – reirab
    Commented Feb 9, 2021 at 5:33

This is a fairly recent development

There used to be liberal Republicans and conservative Democrats. This Doonesbury comic from 1994 was from the tail end of that era. Data pretty consistently bears this out.

Forces have been pushing increased polarization on this issue for a few decades now. I do not personally know a time when "liberal Republican" was not an oxymoron, because by the time I was old enough to pay attention to the news and follow politics, this shift was already close to over.

Essentially, there is a serious and fundamental disagreement over what kind of government we should have. There are two main sides, each one having more or less taken over one of the political parties. It goes back to the New Deal, which dramatically expanded the reach of the federal government and the kinds of things it spent money on, and how much money it raised in the form of taxes. It was controversial then, and it's basically never stopped being controversial since.


As a rule of thumb, it goes along with the (micro)economy. When people has jobs, and those jobs pay a decent liveable wage, people is happy going on with their lives and doesn't care too much for politics. Whenever life gets tough on common people, they start looking at politicians for solutions, and when they don't come, they get angry.

There was a lot of political trouble in the beginning of the XXth century, then it became even worse in the years of the Great Depression, with the societies of the whole world bitterly divided among fascists and communist with almost no middle ground between; then everything went incredibly smoothly in the 50's and 60's despite the Cold War and the possibility of nuclear extinction, thanks to the wonder years of post-WWII economic expansion and, lo and behold, now that having multiple jobs isn't enough to make ends meet, polarization is on the rise again.

Many studies have been made on politics polarization. Unsurprisingly, many noted the strong correlation between unequality and economy stagnation and polarization. This study signals that unequality and trust are the highest predictors of polarization, followed by real GDP. Another one studies the correlation between economic and racial conflicts and its effects over polarization, concluding that identity politics and unequality positevely feedback each other and both increase politics polarization - they note, interestingly, that while unequality does increase polarization, reducing unequality after it has risen to a certain level does not inmediately decrease polarization. In any case, polarization is certainly cyclical and strongly tied to the economy of the commons - it does not matter if the economy of the country is supposedly doing ok, it's the layman's pocket what matters.

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