Thousands of stories have been written about why angry, poor, under-educated white voters put Donald Trump into the Oval Office in a 2016 presidential election that almost every political analyst got wrong. On Thursday, two Princeton economists released a study that sheds some light on how and why this happened.

Death rates among under-educated whites (those with a high school education or less) have now surpassed blacks overall in America. In fact, mortality rates are 30 percent higher for whites between the ages of 50-54 than for blacks overall of the same age, the Princeton economists – Anne Case and Angus Deaton – said in a study released by the Brookings Institution.

“Case and Deaton find that while midlife mortality rates continue to fall among all education classes in most of the rich world, middle-aged non-Hispanic whites in the U.S. with a high school diploma or less have experienced increasing midlife mortality since the late 1990s,” Brookings said about the study.

“This is due to both rises in the number of ‘deaths of despair’—death by drugs, alcohol and suicide—and to a slowdown in progress against mortality from heart disease and cancer, the two largest killers in middle age,” Brookings said.

These are exactly the areas where Trump did his best. He over-performed the most in counties with the highest drug, alcohol and suicide mortality rates, according to Shannon Monnat, a political science researcher at Penn State University. She determined he also did the best in the counties with a large working class and high economic stress.

The combined effect of all of this is that mortality rates for whites in this demographic now surpass the death rates of blacks. According to the study, it grew to be 30 percent higher than blacks two years ago.

It’s hard to sugar-coat these findings. To be brutally honest: mortality rates for people in the middle of their life in rich countries all over the world are falling – except for under-educated whites in the United States.

Rich countries, many of them with universal health coverage, are making progress against deadly diseases such as heart disease and cancer. That clearly isn’t true for poor, under-educated whites in America, this study shows. The findings by Case and Deaton come at a curious time – right as President Trump tried (and failed) to convince Congress to strip health care coverage for millions of poor, under-educated white voters.

The study also shows clearly that “deaths of despair” are rising for both white women and men without a high school degree, and that “deaths of despair” are increasing among this cohort in all parts of America and every level of urbanization. The reason for the increase in death rates is equally as sobering. Basically, the authors said, the economic and social rug has been pulled out from beneath them.

“The authors suggest that the increases in deaths of despair are accompanied by a measurable deterioration in economic and social well-being, which has become more pronounced for each successive birth cohort,” Brookings summarized. “Marriage rates and labor force participation rates fall between successive birth cohorts, while reports of physical pain, and poor health and mental health rise.”

The decline and rise in mortality rates for working-class whites began in the 1970s as the nature of the American economy began to change, and accelerated during the 2008 economic crisis, the authors said.

The research was based on 15 data sets, including government health statistics, death certificates and economic indicators. Case and Deaton, who is a Nobel Prize winner, have been writing about this subject for years. They published a widely-covered paper in 2015 on a similar topic.

There was a “marked increase in the all-cause mortality of middle-aged white non-Hispanic men and women in the United States between 1999 and 2013,” Case and Deaton wrote then. “This change reversed decades of progress in mortality and was unique to the United States; no other rich country saw a similar turnaround.”

That 2015 paper was a startling finding for a global economic power such as the United States. In fact, they said two years ago, the trend had been underway for decades, and that it was only a matter of time before mortality rates for under-educated whites eclipsed that of blacks.

That day has arrived.

The bleak picture that Case and Deaton painted initially is even worse today. Blacks have historically had a much higher death rate than whites. But mortality rates among blacks have dropped considerably in the past few decades – while the rates for working class whites began to rise. The opioid epidemic has made the situation worse, they said.

In sharp contrast, mortality rates for whites with a college degree continue to decline. It is only among working class whites with less education that death rates are getting worse. The disparities in death rates among whites and blacks in the same economic demographic can’t be explained by income alone, they said. Blacks and Hispanics face similar economic hardships as working class whites – but haven’t suffered as much.

“This doesn’t seem to be about current income, it seems to be about accumulating despair,” Case said in a press call. Working class whites, by and large, seemed to have given up the belief that their children would be better off than them in the future, they said.