Photograph by Spencer Platt/Getty

On Tuesday morning, the United States Census Bureau released its annual report on income and poverty in the United States. Ostensibly, it didn’t contain many news-grabbing headlines. In 2013, the number of people living in poverty edged down a bit—from 46.5 million, in 2012, to 45.3 million—and the median household income edged up a bit—from $51,800 to $51,900. (The income figures are adjusted for inflation.)

These developments were positive. The poverty rate fell from fifteen per cent to 14.5 per cent, and the Gini coefficient for equivalence-adjusted income, a measure of over-all household-income inequality that takes into account the number of people in each household, also fell a bit. But all of the changes were minor. In fact, the changes in the median household-income figures and in the number of people in poverty weren’t statistically significant. (In a separate release, which was a headline grabber, the Census Bureau reported that the number of people without health insurance fell by 3.8 million in early 2014, after the Affordable Care Act extended coverage to many new people. Health experts said that the figure actually understated the impact of the A.C.A., probably because the government survey concluded in March.)

The median household is the one right in the middle of the income distribution, and any sign of it doing better, even a bit better, is welcome. Both the uptick in the median income and the fall in the poverty rate reflect the economy’s steady, if unspectacular, recovery from the Great Recession, which hit low- and middle-income people particularly hard. As the recovery continues, more modest gains can be expected.

But there the good news stops. Even in cyclical terms, there is a long way to go before ordinary Americans are able to recover the losses that they suffered during the recession. Median household income was eight per cent lower in 2013 than it was in 2007, when the recession began. And the poverty rate in 2013 was two percentage points higher than it was in 2007.

These figures may help to explain why so many Americans refuse to believe that the economy is recovering, and why President Obama’s approval ratings are stuck at near-record lows despite falling unemployment and accelerating G.D.P. growth. Last month, an NBC News/Wall Street Journal poll found that forty-nine per cent of Americans believe that the United States is in an economic recession. This month, the same poll put Obama’s approval rating for handling the economy at forty-three per cent.

But it’s not just a cyclical story. The central message of the Census Bureau figures is that the same trends that have been roiling the American economy for the past twenty-five years—income stagnation and rising inequality—continue to have an impact. The release from the Census Bureau includes a chart showing inflation-adjusted median household income going all the way back to 1967. Perhaps this picture is already familiar to you. If it isn’t, it should be: it goes a long way toward explaining why Washington politics are so dysfunctional.

Looking at the chart, two periods stand out. In the nineteen-seventies and nineteen-eighties, median household income zigzagged up and down, but, by 1989, it settled at $52,432, which meant that it had risen by about eleven per cent in the previous twenty years. Relative to the so-called “Golden Age” after the Second World War, this was a poor performance. But look at what happened next. In the quarter century between 1989 and 2013, median household income didn’t rise at all. In fact, it fell by about one per cent.

There was some progress in the nineteen-nineties. During the second half of the Clinton Administration, when unemployment fell well below five per cent, median household income rose sharply: in 1999, it reached $56,895. Since then, though, it has fallen by almost five thousand dollars, or close to nine per cent. Consequently, we’re back below where we were in 1989.

The political implications of these figures are, surely, pretty obvious. When spending power is rising broadly, benefitting most social, geographic, and income groups, it is much easier to get rival political parties and factions to coöperate. Consensus politics can thrive, as they did in the postwar era. But when most people’s incomes are stagnating, and have been for decades, politics become darker and more fractious.

With fewer gains to go around, distributional squabbles intensify—not just among various income groups but also among different social classes and ethnic groups. (As the Census Bureau data show, income disparities are still highly correlated with race.) Meanwhile, those lucky folks at the top of the income distribution, where almost all of the incremental income has accumulated over the past couple of decades, have a big incentive to get more involved politically: to prevent the adoption of redistributive policies.

To oversimplify a bit, income stagnation paired with rising inequality is a recipe for political polarization and, under the American system of divided powers, political gridlock, which is what we have. Based on the latest Census Bureau figures, there’s no sign of that changing anytime soon.