One of the big political stories of the moment is rising economic optimism. President Obama delivers his State of the Union speech at a time when he is “clearly benefiting from signs of accelerating economic growth,” in the words of polling analyst Nate Cohn, who adds that the chances of a Democratic victory in 2016 will likely improve “if the economy continues to grow at a healthy pace.”

But here is a flashing warning sign for Democrats: The very voter groups that Democrats need to improve among most are also the ones who continue to say they are falling behind in spite of the accelerating recovery. Those groups are blue collar and older whites.

This trend can be seen in new Pew polling. Ron Brownstein broke down the numbers and found that Obama’s approval is rebounding among key groups in the Dem coalition — nonwhites, younger voters, and college educated white women — and even to some degree among the more GOP-leaning college-educated white men.

But the polling also shows that Obama continues to struggle badly among non-college and older whites. Crucially, Brownstein believes this is connected to the fact that the poll also shows that these voters — non-college and older whites — remain far more pessimistic about their own economic prospects than the more Dem-friendly voters are:

Asked in the latest poll if their income was rising faster, staying about even, or falling behind their cost of living, the blue-collar and older whites offered by far the most pessimistic assessments. About three-fifths of both whites older than 50 and noncollege-educated white men — and nearly two-thirds of noncollege white women — said they are still losing ground. By contrast, a majority of college-educated white men and women said they were either holding steady or gaining ground. Whites under 50, African-Americans, and Hispanics all tilted toward losing ground, but only slightly.

…so long as blue-collar and older whites remain generally downbeat about their personal finances, that pessimism seems guaranteed to reinforce the ideological drift that has carried them securely into the GOP camp.

This is only one poll, but those are striking findings, and if they are right, this will be something important to watch. For one thing, poor and working class whites are right to feel that they are getting shafted economically, as Jamelle Bouie showed the other day. After looking at various economic economic indicators, Bouie concluded: “Between deindustrialization and public disinvestment — as well as ‘trickle-down’ policies that pushed productivity gains into profits, not wages — working-class incomes have been destroyed. A generation of whites has been left behind.”

For another, these are the same voters who overwhelmingly rejected Democrats in the last election. The exit polls showed that candidates like Mark Pryor, Kay Hagan, Bruce Braley and Mark Udall lost by anywhere from large to truly enormous margins among non-college whites and older voters, something that was also true of Democrats overall with regard to the national electorate. Obviously those losses occurred amid GOP-friendly midterm turnout, and at a time when Obama’s numbers were worse than they are now. But nonetheless, Democrats shouldn’t forget that their incumbents underperformed badly among these voters despite emphasizing (to some degree) a slate of economic proposals: A minimum wage hike, pay equity, student loan affordability, expanded pre-kindergarten education, etc.

Democratic strategists believe these proposals did not allay economic anxieties because these voters no longer believe government can solve their economic problems. Strategists also concluded these voters perceive the Democratic Party as more culturally attuned to social issues, and more wedded to transfer programs that help those other people — i.e., the “takers,” — and less focused on representing “hard-working folks who have good fundamental values,” as one Dem pollster put it.

I don’t think this means Democrats should move away from their focus on immigration reform, gay rights, climate change, and other issues that may be alienating those voters (or may not be; it’s a mistake to treat them as a monolith). Quite the opposite: The emerging Democratic coalition whose priorities are shaped around such issues will likely continue to be an enormous asset in national elections, including among some subsets of white voters, such as millennials and socially liberal upscale whites. What’s more, Democrats are obviously less reliant on more culturally conservative whites to win national elections than before.

But one of the big unknowns about 2016 is whether the eventual Democratic nominee will be able to turn out those core voter groups in the numbers Obama did. While this is hardly an original point, this does mean Democrats do also need to think seriously about how to win back alienated older and non-college white voters without compromising their values on other fronts. And they are doing that: It’s no accident that the Center for American Progress — which has ties to Hillary Clinton — just put out a major new policy blueprint on how to fight stagnating wages and restore shared prosperity, which was widely seen as a template of sorts for the story Clinton will try to tell with her candidacy. With all this in mind, the economic attitudes of older and blue collar whites will be key to watch — for political reasons, but also for policy and moral reasons as well.