Ferguson: Paul McLemore, the first African-American to become a New Jersey state trooper, was on the streets of Newark in 1967 when riots triggered by a police beating of a black taxi driver left 26 dead. He spent decades as a civil rights lawyer and years as a municipal judge in Trenton. His wife and children have gone on to enjoy accomplished careers.

“Of course, there’s been a lot of progress” since Newark’s days of rage, he said in an interview on Tuesday. But asked whether a young black man today could find the justice that was believed to be absent in Newark 47 years ago, his response was starkly different.

“No, period,” he said. “There’s pervasive racism — white racism.”

For whites and blacks alike, that duality may be the takeaway from a grand jury’s decision not to indict Darren Wilson, a Ferguson, Missouri, police officer, in the fatal shooting of Michael Brown, a young black man: Much has changed and nothing has changed. A nation with an African-American president and a nascent, if struggling, black middle class remains as deeply divided about the justice system as it was decades ago.

In 1992, a Washington Post-ABC News poll found that 92 per cent of blacks — and 64 per cent of whites — disagreed with the acquittal of the Los Angeles police officers involved in the videotaped beating of a black man, Rodney King.

“What’s striking is just how constant these attitudes have been,” said Carroll Doherty, the director of political research for the non-partisan Pew Research Center in Washington.

In Pew polls, black mistrust of the police and courts is far more pervasive than it is toward other institutions. However, a Pew poll taken earlier this year suggests that African-Americans under age 40 — the demographic that made up most of the people who took to the streets in Ferguson in August — are much less likely than their elders to believe that racism is the main force blocking blacks’ advancement.

That whites and blacks disagree so deeply on the justice system, even as some other racial gulfs show signs of closing, is perhaps not as odd as it seems. Decades of changing laws and court decisions mean that the two races now work together, play sports together, attend school together. But they frequently go home to separate worlds where attitudes and experiences toward the police and courts not only are not shared, but not even understood across the racial divide.

At the end of 2013, 3 per cent of all black males of any age were imprisoned, compared with 0.5 per cent of whites. In 2011, 1 in 15 African-American children had a parent in prison, compared with 1 in 111 white children.

Patricia J. Williams, a Columbia University law professor, said the war on drugs disproportionately affected blacks — in California in 2011, a black man was 11 times more likely than a white to be jailed for a marijuana felony — and three-strikes laws kept many in jail.

Beyond such disparities, “it’s the little things, like stop-and-frisk, like racial profiling and million-dollar block demarcations” — law-enforcement tactics that saturate a high-crime area with police officers — that reinforce blacks’ negative attitudes toward the justice system, she said.

Kenny Wiley, 26, a black man who grew up in a white upper-middle-class suburb of Denver, is one who has seen both sides. The Ferguson shooting, he said, destroyed any notion that his race did not matter — that he could “opt out of the negative parts of blackness.”

“I grew up with a lot of economic privilege,” he said, “and still because of my race and my age and my gender, I’m still in certain situations perceived as a threat. When I walk down the street, they don’t see my SAT score, they see a black man.

“I don’t believe most white people are malicious. I think most white people are oblivious. And I think that there’s a lot of work to do.”

Some blacks take a different view. Brian Willingham, a church pastor and black police officer in Flint, Michigan, said he was conflicted by the grand jury’s decision, but concluded that it was correct.

“I now realise that we who consider ourselves leaders in the black community can’t just be against racism. We have to also be against a portion of black culture that has become increasingly anti-authority and antisocial to a point of self-destruction,” he said.