New Census Bureau numbers released today on income, poverty and health coverage in 2005 are bound to fuel charges that the poor are getting poorer while the middle class continues to be squeezed. See what 25 years of tax cuts for the rich, globalization, and declining union membership have caused? But a look at the numbers inside the report tells a different story.

If we define the middle class as households earning between $35,000 and $75,000 a year, the middle class in America remains a huge demographic group. According to the Census report, Table A‑1, the middle class made up 33.3 percent of U.S. households in 2005. That share is indeed somewhat smaller than in 1980, when 38.2 percent of households earned between $35,000 and $75,000 a year in real (inflation-adjusted) 2005 dollars.

Aha, so the middle class really is shrinking if not exactly disappearing, the alarmists might respond. But the Census numbers also show that over the past 25 years, the share of U.S. households earning less than $35,000 a year has also shrunk, from 44.5 percent in 1980 to 38.4 percent in 2005. Meanwhile, the share of households earning more than $75,000 a year has jumped from 17.4 percent to 28.3 percent.

In other words, if the middle class in America has shrunk, it is only because so many formerly middle-class households have moved to the upper-income brackets, while a significant number of households previously in the lower brackets have moved up to the middle class and beyond.

The solid economic growth of the past two decades has indeed lifted all kinds of household boats. By the most basic measure of real household income, a broad swathe of Americans are better off than they were 25 years ago—thanks to growth fueled in good measure by lower marginal tax rates, expanding trade, and a more flexible domestic economy.