Republican presidential candidate Donald Trump clearly prides himself in shunning focus-group research. He refuses big campaign donations that he asserts make his opponents beholden to special interests. He seems to target no specific constituency.

Many pollsters remain puzzled by Trump’s political appeal. “Republican support for Donald Trump just continues to grow,” said Patrick Murray, director of Monmouth Polling after its August survey, “with no clear sense of who his constituency really is.”

Yet a constituency is emerging. Trump’s strongest supporters, roughly a quarter of Republican voters across the polls, are not dissuaded by any increased media scrutiny of their candidate. They have overlooked a series of faux pas that might have tanked other candidates.

It appears, however, to be a constituency with whom he has barely interacted: white working-class voters. Their lives are far from the flight path of Trump’s private jet, as he zooms from golf course to grand hotel lobby, television sound stage to penthouse suite.

In fact, Trump, a plutocrat who regularly flaunts his extraordinary wealth, is the candidate whose message most closely aligns with sentiments of Rust Belt voters who have lost manufacturing jobs, lack a university degree or are low-wage earners.

Though historically wary of the rich, white working-class voters without a college degree support Trump far more than any other candidate. In Fox News’ most recent poll, 30 percent of the respondents said they back Trump as the GOP nominee, compared to only 21 percent of respondents with a college degree. In CNN’s most recent poll, Trump’s favorability ratings spiked among Republicans, men, people over 50 years of age, as well as people without a university education.

What is the attraction between these strangest of bedfellows?

It is threefold.

First, white working-class voters have proven increasingly unpredictable and unfaithful to any single party. It should not be surprising that they tend to live in many of the most prominent swing states, including Indiana, Iowa, Ohio, Pennsylvania and Wisconsin.

This may look fickle, but it is not indecisiveness. Rather the sense that neither party has done much for them over the past 40 years. The Rust Belt population has confronted post-industrial economic collapse and depopulation. It is fed up with Washington, and cynical about politicians who pledge to address its plight.

This sentiment encompasses much of today’s Republican base. A mere 16 percent of Republicans feel like they are represented in Washington — even though both houses of Congress are currently controlled by the GOP.

Those who do not feel represented support Trump by a sizeable margin, 24 percent to 13 percent for former Florida Governor Jeb Bush, and single digits for the rest of the Republican field, according to CNN’s poll from early August.

Trump’s bombastic declarations that his rivals have been corrupted by corporations and donors (like himself) validates the belief among white working-class voters that the political system is rigged by the very special interests that abruptly closed American factories, laid off American workers and invested money overseas to circumvent American wages and taxes.

Second, Trump addresses people who have felt silenced and sidelined.

Congressmen who once belonged to the working class made up only 2 percent of Congress in 2012. Between 1984 and 2009, the median net worth of a member of the House of Representatives grew from $280,000 to $725,000 in inflation-adjusted dollars.

While Trump will not counterbalance the wealth of American politicians, he validates the views of many ordinary voters as he channels conspiracy theories and whispers from the streets to the stump.

Many white working-class voters, for example, point to often erroneous stories to help make sense of their disastrous fall from grace. These narratives feature characters like the welfare queen who collects checks while driving a Cadillac — a favorite of President Ronald Reagan, who attracted many blue-collar Democrats to the GOP. They also talk about collusion between corporations and politicians because Congress bailed out major banks and car manufacturers in 2008 — but not homeowners underwater on their mortgages. Trump’s off-color remarks about women and minorities, his frustration with “disgusting” people and his baseless assertions about Mexico’s deliberate exportation of criminals across the U.S. southern border fit this mold.

The amplification of these ideas renders credibility to a subset of voters who have felt silenced and sidelined.

“There’s a silent majority out there,” Trump said last month. “We’re tired of being pushed around, kicked around, and … being led by stupid people.”

Third, Trump bluntly acknowledges an acute sense of loss that has been uniquely felt by the white working class.

For white working class people understand loss. The U.S. economy has lost several million manufacturing jobs, which have been replaced by unstable, often contingent work. They lament America’s transition from overt to covert world power. They also sense their own loss of social status in the country they once defined. They feel outnumbered and discomforted by the ascendance of minorities, and disfavored by the elite echelons of American society.

Trump, who talks about losses to China, Mexico and Japan, like a tour by the U.S. soccer team, communicates his awareness of this lost status in simple, blunt terms. Shamelessly showboating his own successes, Trump promises to spread his winnings to a town near you.

This unexpected alignment has given Trump a commanding lead, thanks largely to dedicated support from an objectively small, but relatively large plurality of voters. Because he emphasizes the fact that he is an outsider, Republican voters have overlooked his lack of governing credentials, some wishy-washy statements on social policy and his status as a self-aggrandizing plutocrat.

The strength of Trump’s connection with this constituency of frustrated, silenced people is not likely to recede, given the inability of his Republican opponents to access the financial and political independence Trump wields.

At the same time, he appears unlikely to win if he can’t expand his constituency beyond the white working class, who no longer represent the nation’s mainstream electoral majority.