Will Stancil, a research fellow at the Institute on Metropolitan Opportunity who created the chart, explained to me in an email that

nationally, Trump mostly lagged behind Romney. But in the limited selection of communities where his message hit home, it really hit home, with large gains over Romney really running up the score. These places were very heavily white.

Orfield described the charts in an email:

Trump’s vote skyrocketed in very white suburbs. In the more racially diverse suburbs, particularly those that had been diverse for more than a decade, the white vote for Trump did not increase over Romney’s vote. But in the very white suburbs, particularly in very segregated areas of the Midwest and Northeast, Trump’s vote jumped enormously over Romney’s.

The very white municipalities that voted so strongly for Trump believe that they have reason to worry about the racial stability of their neighborhoods.

Orfield and Thomas Luce, research director at the Institute on Metropolitan Opportunity, reported in a 2013 paper, “America’s Racially Diverse Suburbs: Opportunities and Challenges,” that from 2000 to 2010, the percentage of suburbanites living in areas that were at least 60 percent white fell from 51 to 39 percent.

The percentage of suburbanites living in racially diverse areas — defined as 20 to 60 percent minority — grew over that decade from 38 to 44 percent. Those neighborhoods often remain in flux.

“Fifty-six percent of the neighborhoods that were integrated in 1980 had become predominantly nonwhite by 2010,” Orfield and Luce wrote, “and only 40% of neighborhoods that were integrated in the 1980s remained in that category in 2010.”

Trump’s anti-immigrant, racially loaded messages resonated most powerfully among voters living in the least diverse, most racially isolated white communities. It is in these locales, which are experiencing the earliest signs of minority growth, that anxiety over approaching diversity is strongest.

Put another way, anger, fear and animosity toward immigrants and minorities was most politically potent in the communities most insulated from these supposed threats.

Orfield and Stancil’s work complements findings I reported on in a column last month that showed that Trump performed best in states and communities that were heavily white, but which had experienced relatively small increases in minority populations, notably from immigrants. While small in absolute numbers, the rate of growth represented by these increases was often exceptionally high: For example, if the nonwhite share of the population grew from 2 to 6 percent, the rate of growth was 200 percent.