This article is from the archive of our partner National Journal

When Americans describe their economic lives today, many use words like exposed, vulnerable, and precarious. So long as that's true, it's likely that the two political parties will use the same terms to describe their hold on electoral power.

(Chip Somodevilla/Getty Images)One pillar of contemporary American politics is the inability of either party to sustain a lasting advantage. For generations, it was common for the country to provide one party unified control of the federal government—the White House, House, and Senate—over extended periods. From 1896 to 1968, one or the other of the parties simultaneously held all three levers for 58 of those 72 years. But the Democrats or the Republicans have held unified control for just 12 of the 46 years since 1968, and never for more than four years consecutively.

If anything, the oscillations in the system are growing deeper and more frequent. Any graph of electoral results in this century would resemble a roller coaster. We have careened from the virtual tie of 2000 to strong Republican elections in 2002 and 2004, to the sharp recoil back toward Democrats in 2006 and 2008, to Republican waves in 2010 and 2014, sandwiched around President Obama's solid reelection in 2012.

Since 1968, changes in the country's demography and the parties' coalitions have inverted the nature of the standoff: We have moved from a system where Republicans dominated the White House and Democrats the Congress, from 1968 until 1992, to the reverse in the years since. But the constant has been a fragmentation of authority that has denied either side the opportunity to impose its agenda in a lasting way.

That dynamic has many causes, from changes in the media and campaign finance to the overlapping demographic, generational, and geographic realignments that have divided the country almost exactly in half, allowing even small shifts in sentiment to repeatedly tip the balance. But it's not a coincidence that this period of heightened electoral fragmentation coincides almost exactly with an era of intensified economic uncertainty for more Americans.

After doubling in constant dollars from 1947 through 1973, the median income—the standard of living for the average American family—has increased only 5 percent since. Inequality in income and wealth has reached historic heights. The median income is lower today than it was in 2000—marking a period of sustained stagnation almost unprecedented in American history. In the trenchant phrase of The New York Times' David Leonhardt, America is now "living through the great wage slowdown of the 21st century."

The frustration, anxiety, and even fear generated by this breakdown reverberate through the results of both the Edison Research exit poll conducted on Election Day and the latest Allstate/National Journal Heartland Monitor Poll released over the past week. In the exit poll, roughly four-fifths of voters surveyed described themselves as "very" or "somewhat worried" about economic conditions. Seven in 10 described the national economy as either "not so good" or "poor." Only about one in five thought life for the next generation would be better than it is for today's.

In the Heartland Monitor Poll, which focused on the balance between work and home, a solid 55 percent majority of adults described their personal financial circumstances as only fair or poor; just one-fourth of adults said President Obama's economic agenda was improving their opportunities; and nearly half of women said that it was not just tough or difficult to succeed both at work and at home, it was simply impossible. While a majority of current workers said they were very satisfied with their jobs overall, only 31 percent expressed that level of contentment with their pay.

These problems aren't unique to the United States. As Brookings Institution senior fellow William Galston wrote in an important recent paper, under the pressure of global competition and technological change, free-market democracies throughout the West are no longer producing "rising living standards for all." Across Europe, that failure is driving greater electoral and parliamentary fracturing, as frustrated voters desert the mainstream governing parties for more-ideological alternatives, particularly far-right populist parties such as France's National Front and Great Britain's UKIP. This soil is also nourishing secessionist movements, such asScotland's narrowly defeated recent effort.

In the United States, these pressures are deepening disillusionment with both parties. In the exit poll, most of those surveyed expressed negative opinions about Obama, Congress, Republicans, Democrats, and every major potential 2016 presidential contender tested. In the Heartland Monitor Poll, few Americans said they believed they would significantly benefit if either party held unified government control. "Broad prosperity is ... the glue that binds our society together," Galston warns. "Economic stagnation means a continuation of gridlocked, zero-sum politics."

The skepticism that either party can solve the most ominous problem facing most Americans—their inability to get ahead as quickly as they anticipated—is an acid that's corroding both sides' public support. As long as it keeps dripping, even victories as resounding as the GOP's breakthrough this month risk immediate reconsideration in the next election.

This article is from the archive of our partner National Journal.

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