Like the hedgehog, Donald Trump understands only one thing that matters. His critics, such as George W. Bush, Barack Obama, and Jeff Flake, who last week made three largely correct and inspiring speeches, seem to know everything but.

They understand politics, policy, and the uses of etiquette, but seem deaf, dumb, and blind from the central great issue that drove Trump’s election: The top tiers of the country have been flourishing nicely, while those underneath have been taking a beating. And one reason is international trade.

Like Hillary Clinton and the sixteen extremely well-qualified candidates who lost to Trump in the primary, these well-meaning, cultured, intelligent people seem unable to grasp what Roger Altman explained in the Washington Post this past weekend: that “the so-called American dream ... has ended for most of our citizens. Half of the young adults in this country will earn less over their lifetimes than their parents did. Indeed, the whole idea of rising living standards, which defined this country for so long, is a thing of the past.”

Trump won, not because the country was racist or sexist, or because most in the country enjoyed his coarse language. He won because he was the only one who realized the problem existed.

Trump was elected by people who didn’t much like him — 19 percent of his voters thought him unqualified — and by Obama voters in the upper Midwest whose communities had been devastated by job losses. The irony was that Bush, Flake, and Obama, while deploring Trump’s sins, still listed free trade as one of their paramount values, even though the evidence since has been more than abundant that embracing free trade beyond the limits of prudence was their founding and critical sin.

On Oct. 10, 2000, on the advice of the experts, Bill Clinton signed a now-infamous trade deal with China, calling it a ‘win-win’ solution for both of the countries that would create hundreds of thousands of jobs. It turned out the experts were wrong. It created job losses that were worse than expected. Workers didn’t ‘bounce back,’ as experts predicted, but remained unemployed. These losses fanned out in concentric circles of failure, as losses of wages led to failures of stores, restaurants, and local businesses in their localities, as entire districts fell into decline.

Along with this, and caused by it, came a radicalization of politics. “In the 2000s, congressional districts where competition from Chinese imports was rapidly increasing became more politically polarized,” the Wall Street Journal reported in August 2016. A study by four economists released late last November reported that districts represented by moderate Democrats in 2002 were likely to be represented by liberal Democrats or conservative Republicans eight years later. The moderate Democrats vanished. This foretold the rise of both Trump and of Bernie Sanders.

In the 2016 GOP primaries, Trump won 89 of the 100 counties mostly deeply affected by the Chinese invasion, his pessimism and anti-trade talk “tapping into sentiments ... largely ignored by conventional” voices. The study concluded that “if Chinese import gains had been 50 percent smaller,” Trump would have lost Pennsylvania, North Carolina, Wisconsin, and Michigan, and Hillary Clinton would have been president. The bill her husband signed sixteen years earlier ended up breaking her heart.

In the primaries, the election, and now in the aftermath, Trump’s critics have been eloquent in outlining his faults without understanding the reason he beat them, which is their great failing. Is no one around who comprehends why this happened — without his huge and quite frightening flaws?