Once again, Donald Trump pummels reality to please his base. As often, his cudgel is race.

His Justice Department, the New York Times reports, is investigating colleges, including Harvard, whose admissions policies supposedly disfavor whites and Asians to benefit blacks and Hispanics. This is perverse, for the evidence shows that those minorities continue to be underrepresented on American campuses.

Indeed, in the last 35 years this gap has widened. A comprehensive study by the Times shows that the percentage of black freshmen at elite schools is virtually unchanged, and that the increase in Hispanics has not kept up with their growth rate overall. The same holds true at top liberal arts colleges and public flagship universities, including the University of California in America’s most diverse state.

In 2003, the Supreme Court found that promoting diversity on campus is a legitimate consideration in admissions policy. But according to the Department of Education, since that ruling we have seen little progress.

As of 2014, the African-American population in four-year colleges had risen 1 percentage point, to 13 percent, over the preceding decade. Hispanics were up only a little more. Yet Trump’s DOJ, according to the NAACP Legal Defense and Educational Fund, is “attempting ... to achieve what they have not been able to do with the Supreme Court” — discourage affirmative action.

Why? As usual, Trump is subordinating reality to racism.

His campaign thrived on deliberately stoking racial anxieties and resentments. Surveys show that a belief that whites are treated unfairly is a powerful predictor of support for Trump. Similarly, his adherents are more likely to feel that the growth of racial or ethnic groups is negatively affecting our society.

These feelings pervade the GOP electorate. A 2017 survey showed that 43 percent of Republicans believe there is significant discrimination against whites, whereas only 27 percent of them believe the same for blacks. As Thomas Edsall spelled out in the Times, Trump benefits from a “white identity politics” among voters who want the advantages they imagine accrue to minorities.

Now Trump’s presidency is reeling. His attack on affirmative action on campus is red meat for white people, demonstrating he will correct the passion for diversity which, his followers believe, limits white opportunity by skewing college admissions.

Thus does bigotry bury what, for the GOP, is a highly inconvenient truth. According to The Washington Post: “At 38 top colleges in the United States, more students come from the top 1 percent of income earners than from the bottom 60 percent.” It is income inequality, not race, that disadvantages lower-bracket whites.

But for Republican ideologues and cynics, reverse discrimination in admissions is a politically potent myth, energizing the base while providing cover for policies favoring the wealthy. Nowhere is this pernicious stalking horse more empowered than among Republican judges on the Supreme Court, to whom Trump will ultimately look to banish affirmative action.

Principal among them is Chief Justice John Roberts. It was in opposition to affirmative action in admissions that he wrote his famous dictum: “The way to stop discrimination on the basis of race is to stop discriminating on the basis of race.”

This excruciating platitude does not withstand exposure to the world as it actually exists, including in college admissions. Such banality is, perhaps, to be expected from a smug country clubber, smiling benignly at the waiter who has just served up his favorite single malt scotch. But from America’s chief justice, it drives rulings that serve the ideology and electoral interests of the GOP at the cost of justice for minorities.

This effort is epitomized by Fisher v. University of Texas, the most recent challenge to affirmative action before the Supreme Court.

At issue was a modest plan allowing the university to consider race as one of many “plus factors” in some students’ admissions decisions. The white plaintiff conveniently overlooked that of the 47 students admitted with lower grades and test scores, 42 were white. A narrow majority of justices upheld the Texas program.

Roberts dissented. At oral argument he demanded to know: “What unique perspective does a minority student bring to a physics class?”

Seriously? Does Roberts really imagine that this is about the principles of physics? What about those disadvantaged students — minorities and the poor — who the university sought to help? Or what students of all backgrounds experience as part of a diverse student body? His calculated obtuseness exposes the GOP’s attack on affirmative action for what it is — a callous sham.

But there Roberts remains, awaiting the next attack, which beyond doubt will be supported by Donald Trump.

First published in The Boston Globe.

Richard North Patterson’s column appears regularly in the Boston Globe. His latest book is “Fever Swamp.” Follow him on Twitter @RicPatterson.