WASHINGTON ― Remember when pundits hailed the election of Barack Obama as the beginning of a “post-racial” America?

After the election of Donald Trump to the presidency, it seems like a distant memory. But in 2008, it was the prevailing wisdom among political commentators.

Cornell Belcher, a long-time Democratic pollster who worked on both of Obama’s presidential campaigns, started seeing through the mirage of racial harmony well before Trump’s election made it obvious. In Belcher’s book, A Black Man in the White House: Barack Obama and the Triggering of America’s Racial-Aversion Crisis, released weeks ahead of Trump’s election, he presents years of research showing that white resentment grew steadily under Obama.

He too had hoped Obama’s presidency would usher in a period of post-racial politics. But in his public opinion research in the ensuing eight years, he told HuffPost on Thursday, he saw a “rise in racial aversion ... which accumulated in a sort of perfect storm for a candidate like Donald Trump.”

To measure “racial aversion,” Belcher surveyed people’s responses to “a range of questions ... from affirmative action questions to government doing too much for people of color, to people of color not being as patriotic.”

The answers, collected over the course of eight years, showed a hardening of white attitudes toward people of color. Belcher attributes that trend not just to Obama, but to the rising coalition of communities of color that elected Obama.

Obama won reelection with just 39 percent of the white vote nationwide, not just by turning out more people of color, but also by taking advantage of the fact that the country simply had more voting-age people of color to turn out, Belcher noted. The changes that made that victory possible scared many of the white voters who went on to vote for Trump, according to the pollster.

Trump “is a George Wallace-like historical figure. The difference is that George Wallace could not win the Republican primary. He couldn’t win the nomination and become president,” Belcher said.

“But Donald Trump could, because now, with the rise of really, not Obama, but the Obama coalition, the wolf is now at the door,” he continued. “And what I mean by the ‘wolf is at the door’ is, I mean America is going through dramatic shifts, demographic shifts.”

Now Belcher is warning against Democratic analysts who see a message of economic empowerment alone as the key to rebuilding the party.

“[The country is] only going to get browner, so we have to solve for this, or we lose the future,” he concluded. “And again, that’s not pointing fingers at so many working-class whites, who, you know what, their world has changed, and the changes that are happening in our country, in this country, are stark. And we shouldn’t be surprised that some people are uneasy about it. But we should have that conversation about that unease, and a prescription about that unease that doesn’t pit us against each other.”