Nor are they voting — or at least not as much as people with jobs. In 2010, some 46 percent of working Americans who were eligible to vote did so, compared with 35 percent of the unemployed, according to Michael McDonald, a political scientist at George Mason University. There was a similar turnout gap in the 2008 election.

No wonder policy makers don’t fear unemployed Americans. The jobless are, politically speaking, more or less invisible.

It wasn’t always so. During the Great Depression, riots erupted on the bread lines. Even in the 1980s and 1990s, angry workers descended on Washington by the busload.

“There used to be a sense that unemployment was rich soil for radicalization and revolt,” says Nelson Lichtenstein, a professor of labor history at the University of California, Santa Barbara. “That was a motif in American history for a long time, but we don’t seem to have that anymore.”

But why? It’s partly because of the greater dispersion of the unemployed, and partly because of the weakening of the institutions that previously mobilized them.