President-elect Donald Trump won several states that had long been Democratic, like Pennsylvania, Wisconsin, and Michigan, as well as swing states, like Ohio and Florida, on his way to a seemingly improbable electoral victory earlier this month.

Chris Arnade, an independent journalist who has spent the past four years traveling the US to document the opioid crisis, was one of the few who weren't surprised. After traveling tens of thousands of miles in working-class communities along the Rust Belt and elsewhere, he found one constant.

"Wherever I saw strong addiction and strong drug use," Arnade told Business Insider, he saw support for Trump.

Official voting data has suggested a similar correlation. Since the November 8 election, Shannon Monnat, a rural sociologist and demographer at Pennsylvania State University, has dug into the results. She found that counties that voted more heavily for Trump than expected were closely correlated with counties that experienced high rates of death caused by drugs, alcohol, and suicide.

Two other factors were strongly correlated with Trump "overperformance," Monnat found: the percentage of white voters in the county and its ranking on Monnat's "economic distress index." The index, which Monnat has used in her research for years, combines the percentages of people who are in poverty, unemployed, disabled, in single-parent families, living on public assistance, or living without health insurance.

Monnat wasn't surprised by the correlation.

"I expected to see it because when you think about the underlying factors that lead to overdose or suicide, it's depression, despair, distress, and anxiety," Monnat told Business Insider. "That was the message that Trump was appealing to.

"People are literally dying," she added. "There was such a sense of hopelessness that it makes sense they would vote for massive change."

Courtesy of Shannon Monnat That correlation surfaced across the US, not just in areas of heavy Trump support like Appalachia and the Rust Belt, Monnat said. Even in counties with high mortality rates relating to drugs, alcohol, and suicide that Trump lost, he overperformed relative to 2012 Republican nominee Mitt Romney.

Historian Kathleen Frydl, who has closely followed the opioid crisis, noticed a similar phenomenon unfolding on election night. Traditionally blue counties that she knew to be hard hit by opioids were flipping to Trump.

After "recovering from the shock," she began comparing the drug-overdose death rate with voter performance in critical states such as Ohio, Pennsylvania, Wisconsin, and Michigan.

What she found was striking.

Six of the nine Ohio counties that flipped from Democrat to Republican in 2016 logged overdose death rates far above the national rate of 14.7 people per 100,000. Nearly every Ohio county with an overdose death rate above 20 per 100,000 saw voting gains of 10% or more for Trump compared with Romney and/or drops of 10% or more for Hillary Clinton compared to President Barack Obama in 2012. Only Butler County, home to Miami University, and Hamilton County, the jurisdiction for Cincinnati, did not conform to this pattern.

Twenty-nine of 33 Pennsylvania counties with overdose death rates above 20 per 100,000 conformed to the same pattern and/or flipped from Democrat to Republican entirely. (You can see Frydl's comparison of county vote totals and overdose death rates here.)

The phenomenon led Frydl to dub such voters the "Oxy electorate."

'A sea of correlations'

The Economist found similar voting trends, though it argued that combining life expectancy and public-health metrics, such as obesity, heavy drinking, and physical activity, was the most accurate predictor of Trump's outperformance of Romney.

Even in the Ohio counties that The Economist pointed to as evidence of its analysis — Knox and Jefferson — the overdose death statistics bear out. Jefferson County, whose margin of victory for Trump was 30 percentage points higher than Romney's compared with 14 points for Knox, according to The Economist, had an overdose rate in 2015 of 28.8 per 100,000. Knox's was nearly half that, at 15.1 per 100,000.

Renowned statistician Nate Silver, the editor-in-chief of FiveThirtyEight, argued on Twitter that education levels were still the most accurate predictor of Trump voting trends and that linking heroin deaths with voting was a "spurious correlation." Many analysts have pointed to percentage of non-college-educated white males as the leading predictor of Trump performance.

Frydl said, however, that there was a "sea of correlations" uniting these communities across the US, noting overdose deaths rates, mortality rates, education levels, and race, among others. And while she said "correlation does not equal causation," the characteristics can help analysts understand why Trump’s campaign had such appeal.

Similarly, Monnat suggested that the rates of drug-, alcohol-, and suicide-driven mortality she looked into were not in and of themselves enough to explain why voters gravitated toward Trump. Rather, she said, they are "reflective of the structural problem."

These are communities that feel "marginalized" and "left behind" by globalization and the larger economic structure that has taken place over the past several decades, Monnat said. These are communities that have lost high-paying manufacturing and mining jobs, have seen their downtowns gutted for Walmarts and big-box stores, and have seen low-wage service jobs fill in the employment gap.

In these communities, it's not just about an economy that's failing them, Arnade said, but how the very structure of their communities has changed, for both rich and poor. Social networks have become "broken" and people feel "humiliated," he said.

'America does not seem great'

The Hard Times Tavern seen in Fort Gay, West Virginia, in 2014. REUTERS/Robert Galbraith

The coming of the opioid crisis in the Rust Belt and Appalachia felt a lot like the economic problems that preceded it — something over which its residents had no control.

People were unprepared for the opioid crisis and, "what's more, believed they had done nothing to deserve it," investigative journalist Sam Quinones wrote on his blog Monday. Quinones investigated the causes of the opioid crisis extensively in his 2015 book, "Dreamland: The True Tale of America's Opiate Epidemic."

"The effects of opioid addiction ripple out far beyond addicts to affect entire communities," Quinones wrote, killing their "buoyancy of spirit" and leaving them open to the "foreboding that seemed to motivate many voters."

In an interview with the Columbia Journalism Review, Arnade described the prototypical "white working class" community that he visited: Prestonsburg, Kentucky, a coal town of 3,500 residents, most of them white. Here's how he described its turn toward Trump:

"There's a real strong sense of community, but the entire community is feeling humiliated. The whole town feels like it's suffering, and with the economic decline has come a large increase in the things that follow: addiction, breakup of families. The place feels very hurt."

"And in comes Trump with a message of restoring pride — partly through white identity — that resonates there, because from Prestonsburg, Kentucky, America does not seem great."

Trump's attack on immigration and globalization was the perfect "one-two punch" in a place like Prestonsburg, Arnade said. It "punches downward" by scapegoating others, like immigrants and minorities, and upward at what the working class views as a "rigged system" pushed by politicians with "fancy educations."

But Arnade said it was too easy to vilify such voters as "racist and stupid," even if Trump's racial appeals may have resonated. Many Trump voters in those communities, he said, voted for Obama and were voting "to kick over the system."

'A social policy failure'

WCPO/Screenshot

Frydl described the movement from economic decline to opioid crisis to Trump support as "a nested chain of causality," wherein the anchor is the loss of industry and economy in the Rust Belt and Appalachia.

Frydl too saw the Trump win in such areas as a vote against the status quo in the same way that a vote for Obama was in 2008. In that way, she thinks Trump's upset is a "de facto" judgment on Obama's failure to be the "change agent" many thought they were voting for.

"The people in Pennsylvania, Ohio, and the steel belt that voted for Trump were aware that the steel mills closed in 1983," she said. "They were aware of that in 2012 when they voted for Obama. There is something specific to the opioid crisis in the last four years that is a social policy failure that deserves to be treated as discrete."

Frydl, who has written a history of the drug war in America, believes that the Obama administration’s response to the opioid crisis signaled to many addiction-ravaged areas that "their suffering was not registering with the Democratic Party establishment."

The administration's landmark bipartisan bill passed earlier this year to address the crisis, the Comprehensive Addiction and Recovery Act, was seen as modest, at best. Attorney General Eric Holder failed to hold Purdue Pharma, widely considered to be the main source for opioid overprescribing in the 1990s and 2000s, or other pharmaceutical companies to account for their part in the crisis, Frydl said. And even as the government cracked down on legal prescription drugs, heroin from Mexico and synthetic opioids from China flooded in to meet demand.

After decades of systemic economic decline and the government's failure to address the subsequent public-health crisis, Trump's outsider campaign was perfectly primed to capitalize on the so-called Oxy electorate's fears about foreign influence and loss of status.

"I'm not sure why we didn't think it would impact the presidential election," Monnat said. "It's finally come to bear, and we're going to have to deal with the repercussions of that."