What the data above suggests is an erosion of confidence that things will keep getting better for future generations that began in late 1990 and has continued — with a brief interruption in the wake of the Sept. 11, 2001, terrorist attacks and rallying effect it occasioned — all the way to the present.
That number goes hand in hand with the next question asked by the NBC-WSJ pollsters. People were asked which of these two statements came closer to their view: 1) "The United States is a country where anyone, regardless of their background, can work hard, succeed and be comfortable financially" or 2) "The widening gap between the incomes of the wealthy and everyone else is undermining the idea that every American has the opportunity to move up to a better standard of living." A majority — 54 percent — chose the second statement while 44 percent chose the first. That is, a majority of people believe that the chasm between rich and poor is making it harder and harder to achieve the American dream.
President Obama addressed the uncertainty and pessimism of many people recently in a speech at, of all things, a fundraiser in Seattle, Washington. He said, in part (bolding is mine):
It's hard to overestimate what it could mean to politics if the idea that our country is marching forever toward a better future fades or disappears entirely. So much of every politician's patter — Democrat or Republican — is built on the idea that America has always overcome hard challenges, always made things better for our kids than for us, always had achieving the American dream as a real possibility. A large bloc of the electorate no longer believes any of that.
This may be, as Obama suggests above, a transitional phase — that once a "new order" is established the uncertainty and pessimism of the public dissipates or disappears. But, the depth of the uncertainty about the future also leaves open the possibility that the idea of a forever-improving America may be a thing of the past in the minds of many of its citizens. That's totally uncharted political water.