This post is part of Polyarchy , an independent blog produced by the political reform program at New America , a Washington think tank devoted to developing new ideas and new voices.

There is a debate emerging on these pages (and elsewhere) as to whether the Democrats are in deep trouble.

Vox's Matt Yglesias thinks they are. Not only, he notes, do Republicans now hold majorities in the US House and the Senate, but the GOP also now has unified control of 25 state legislatures, while Dems control only seven. More significantly, Republicans are using their power. They are going after unions, which have traditionally been a key organizing force for Democrats. And they are enacting stricter voting rules, which tend to disenfranchise those voters most likely to vote for Democrats.

Political scientist Phil Klinkner has disagreed, arguing that there is a natural, almost "thermostatic" ebb and flow to partisan fortunes in America. When one party controls the White House, public opinion naturally moves against that party. Put a Republican in the White House, he argues, and voters across the country will readjust to favor Democrats.

Who is right? It depends on whether you think American democracy operates primarily by balancing feedback loops (in which partisan electoral victories are always short-lived because they provoke an equal but opposite reaction) or primarily by reinforcing feedback loops (in which electoral victories translate into policy victories that can cement long-term advantages).

Almost certainly, it's a little bit of both. But the timelines on which these loops operate vary. Reinforcing feedback loops are likely to prevail for the immediate future, possibly even for decades. Balancing feedback loops operate over much larger timescales.

Or, shorter version: Yglesias is probably right. Democrats likely are in deep trouble for the next few decades, barring any unexpected changes.

The macrohistorical perspective

While party fortunes certainly do ebb and flow from election to election (and, yes, in some opposition to White House control, as per Klinkner and others), these ups and downs are secondary to a larger pattern in American politics. Traditionally, there has always been one dominant and one secondary party — a "sun" party and a "moon" party, as Samuel Lubell once famously labeled it.

And this dominance tends to last for a very long time. The below (borrowed) chart tells a straightforward story. Republicans had mostly solid control of Congress for about 70 years following the Civil War. Then Democrats had pretty solid control of Congress for 60 years.

Since the mid-1990s, things have been unusually up for grabs. The past two decades have been the most consistently competitive period in American history (which Frances Lee has convincingly argued is a key driver of our particularly nasty bout of partisanship).

But more and more evidence suggests that Republicans may come out as the long-term winners. As Thomas Schaller has convincingly argued, the GOP increasingly enjoys a structural advantage based on geography — suburban and rural areas, where Republicans do best, are overrepresented in Congress. Republican voters also turn out more reliably because of their stronger social networks.

Moreover, as Schaller notes, 39 of 50 US states hold gubernatorial elections in off-year or odd-numbered-year elections, when turnout is lower. John Judis has made some similar arguments about the long-term strength of Republicans.

But perhaps more significantly, Republicans are taking advantage of being in power to strengthen future electoral success.

Yglesias describes some of these strategies (weakening unions, raising hurdles to voting) in his piece. Jacob Hacker and Paul Pierson have also provided some excellent descriptions of the ways in which Republicans have used their electoral gains to strengthen their core constituencies (mostly the very well-off) while weakening Democrats' core constituencies (those who are less well-off), increasing socioeconomic inequality in the process.

Since Democrats are the party of big, especially federal, government, political dysfunction in Washington hurts Democrats

Hacker and Pierson additionally argue that voter ignorance has also helped Republicans, especially the most conservative Republicans. As they point out, there is considerable political science evidence that political messaging does mislead voters, undermining responsiveness. And, as both Schaller and Hacker and Pierson both point out, Republicans have figured out a brilliant smoke-and-mirrors strategy: Since Democrats are the party of big, especially federal, government, political dysfunction in Washington hurts Democrats. Republicans may be the instigators, but most voters don't play close enough attention to politics to ascribe meaningful blame. They just see that they don't like big, federal government, and Democrats are the party of big, federal government.

How voter ignorance helps the political right, across nations

Voter information is also at the core of another feedback theory, one that I'm going to spend a bit of time on here because it makes a compelling case for why our future may be more inequality and more Republican dominance, and how those two features are actually closely tied together.

This theory comes from political scientists Torben Iversen and David Soskice, and is laid out in a recent academic journal article, "Information, Inequality, and Mass Polarization: Ideology in Advanced Democracies."

Drawing on considerable data across 20 democracies, they identify two "Weberian ideal types" of democracies.

The first of these types, exemplified by Scandinavian countries like Sweden and, yes, Denmark, tends to have relative equality in educational opportunity and strong private sector unions. This leads to denser social networks that discuss politics, and as a result, even those who are less well-off tend to be pretty well-informed and engaged politically.

Thus, there tends to be a pretty strong relationship between socioeconomic status and ideological self-placement in these countries, with those who are worse off economically mostly identifying on the political left. These countries are also marked by high polarization, largely a product of a very informed electorate (high information and strong ideology tend to go together).

The second of these types, exemplified by the United States, has high levels of economic inequality and right-leaning politics. These countries have unequal educational opportunities between rich and poor and weak private sector unions. These two factors produce a public in which the lower end of the socioeconomic spectrum tends have low levels of political engagement and very limited information.

As a result, their socioeconomic position tends to be a poorer predictor of ideological self-placement. Those individuals lower on the socioeconomic spectrum are much less likely to place themselves on the political left, as compared with the Scandinavian countries. The mass electorate also tends to be less polarized (at least based on self-reported ideology), which Iversen and Soskice argue is a sign of their low levels of political information. Other countries in this cluster are the UK, Ireland, and Greece.

Below is the visualization of their "micro-level" theory:

To summarize the picture above: Education and union membership contribute to knowledge, both directly and indirectly, by facilitating networks that stimulate more political discussion. Socioeconomic status also contributes to knowledge directly — wealthier individuals tend to be more well-informed.

Political knowledge is the key variable here. The more political knowledge an individual has, Iversen and Soskice argue, the more closely ideology and economic status go together.

"We find," they write, "that political knowledge causes more polarized self-placements, but that political knowledge has a bigger effect on the left than on the right, and that the distribution of knowledge is biased in favor of the right."

Put another way, those who are less well-off need unions and public education to get them the political information they need to self-place in line with their economic interests. The rich do not.

At the macro level, Iversen and Soskice sketch out a national feedback loop.

In countries with strong unions, strong investment in public education, and generally informed citizens, politics tends to be left-leaning but also highly polarized. More left-leaning governments invest more in public education and support strong unions. The cycle reinforces itself.

By contrast, in countries with low spending on education and weak unions, mass political information declines. Because those who are less well-off lack information to properly locate their economic interests, politics trends rightward, and inequality increases as a result of further de-investment in education and declining union bargaining power, which further reduces political information. And so on. As Iversen and Soskice explain, "In this cluster of countries, we further expect politics and public policies to be shifted to the right because of the strong class bias in political information."

Does this explain what's going on in the United States?

Much in this theory is consistent with recent trends in the United States. Unions have declined. Income inequality has increased. The educational opportunity gap has widened. The political mood has shifted to the right. More and more, the poor have dropped out of politics.

Republicans might respond by pushing back against the assertion that working-class Republican voters are making a mistake. After all, perhaps these voters actually understand what a bunch of pointy-headed academics from Harvard and the London School of Economics (where Iversen and Soskice, respectively, teach) never seem to grasp: that free market policies produce more prosperity for everyone, and that too much government regulation is slowing down the economy. Or maybe the struggling working-class voters think Democrats have done little to help them in recent years, so why not vote Republican. And besides, aren't the Democrats too in thrall to their wealthiest donors to do anything really big to lift the fortunes of those who are worse off? Aren't Democrats just a bunch of elitists who don't really care about the poor?

By the logic of Iversen and Soskice, this is exactly the uncertainty that makes it hard for low-information voters to determine who actually represents their interests. They hear a bunch of competing arguments over economic policy and government performance. How do they know which to believe?

To be fair, surveys do show that Americans tend to be willing to tolerate a certain amount of inequality, especially to preserve free enterprise and individualism. But Americans also significantly underestimate the amount of inequality in society, and would probably be much more unhappy if they accurately estimated it. After taxes and transfers, the US is the most unequal of the advanced industrial democracies.

Obviously we are not Denmark. Or Sweden. And it's not clear how we would become Denmark or Sweden. But this seems to me precisely Iversen and Soskice's point: These reinforcing feedback loops are quite sticky. Once a country gets into a particular pattern, a whole bunch of factors make it very hard to break out of that trajectory.

What should Democrats do?

All these reinforcing loops described above point in the same direction: If Democrats think they can just wait for the public to get tired of Republican rule, they are going to be waiting a long time. Maybe half a century.

One of the intriguing, unresolved questions in the Iversen and Soskice paper is the role that electoral systems play. The left-leaning, equalizing Scandinavian countries tend to be multi-party proportional representation systems; the right-leaning, increasingly unequal countries tend have majoritarian systems with two or three parties.

The US is the only major democracy with just two effective parties, and has one of the lowest voting rates of all democracies

As Iversen and Soskice note, "Because education spending and strong unions in turn lead to more left-leaning voting, there is likely to be a reinforcing feedback loop between left policies and left voting in PR systems."

There is some evidence that because multi-party systems have several parties competing for voters on the left, politicians in these countries do more to mobilize the undervoting poor. Multi-party systems also tend to have higher voting rates. The US, by contrast, is the only major democracy with just two effective parties, and has one of the lowest voting rates of all democracies.

Certainly Democrats have plenty of incentives to mobilize the poor, who do tend to vote Democratic. But because of declining union infrastructure, various forms of disenfranchisement, and the weak social networks of the lower class, organization is difficult and costly. Moreover, the Democrats' most active donors may not be super eager to see the poor get super engaged in politics.

Something significant may happen to upset the self-reinforcing feedback loops that appear to be in play. A major shock, like a serious economic upheaval (say, an automation revolution), or a bitter civil war that fractures the Republican Party, could reorder things. Or Democrats could come up with a new and brilliant strategy.

But absent something significant, get ready: American politics is probably going to look like it does right now for a few decades to come.

VIDEO: How wealth inequality is dangerous for America