Pew Research has been asking this polling question for over 40 years, and the recent trend line is revealing:

That rise and dip in the past year is astonishingly significant.

Observations from Kevin Drum:

First, as a baseline, you’d expect lots of yes answers to this question because a big part of the population consists of young people who are graduating from high school/college, getting jobs, getting married, having kids, getting promotions, etc. Most people in their 20s and 30s have rising economic fortunes regardless of their long-term prospects. And that’s exactly what we see up until about 2000.

Second — oddly — recessions seem to have little effect on how people respond to this question. There aren’t enough data points to say this with certainty, but I’ve overlaid recessionary periods in red and they really don’t seem to map at all to downturns in average optimism. Until 2000, that is. The 2001 recession maps to an initial drop in optimism in 2002, followed by another drop in 2005, followed by a complete collapse in 2008. As a result the percentage of people who think they’re better off now than five years ago has dropped from about 56% in the 2000 data point to 41% in the 2008 data point. This is by far its lowest point ever.

My guess is that part of this is a result of the end of the baby boom and the graying of the American population. But only a small part. Almost certainly the bulk of this downturn is due to the fact that the Republican economy of the past seven years has been aimed like a laser at improving the fortunes of the affluent, with the result that for the first time in recent memory an economic expansion — a long economic expansion — hasn’t improved the fortunes of the middle class even slightly. After seven years of this, the working and middle classes are finally starting to realize that this isn’t likely to change.

Good news, I think, for the upcoming elections.