Decision by decision, the Republican-appointed Supreme Court majority is hardening America’s division into a two-tier society. The result is that even as racial minorities are growing into a majority of the nation’s future students, workers, taxpayers and voters, the court’s new rules are entrenching the dominance of White people in the key leadership positions of American life.

That’s a formula for sustained tension between rising generations pressing for greater inclusion and a thicket of legal barriers protecting those already in power. The most immediate flashpoint will come in Congress and in several southern states, where lawmakers are poised to redraw their electoral maps to roll back non-White representation if the high court ultimately allows them to.

In many respects, today’s Supreme Court majority is following the path marked by the late 19th-century court. After the Civil War, the Republican-controlled Congress, in a process known as Reconstruction, passed a monumental trio of constitutional amendments — the 13th, 14th and 15th — to guarantee the rights of the newly freed slaves, as well as a succession of federal laws to ensure enforcement of those rights. But, starting in the 1870s, the conservative Supreme Court of that era unravelled those protections in rulings that culminated in the 1896 Plessy v Ferguson decision that upheld “separate but equal” Jim Crow segregation for nearly the next 70 years.

Today’s Supreme Court majority has not matched that nadir. But the conservative majority on the modern Court has steadily retrenched the landmark civil rights protections enacted during the 1960s — a period that historians often describe as the nation’s Second Reconstruction.

“It is not as if the same things are happening the same way,” University of Connecticut historian Manisha Sinha, author of an acclaimed 2024 history of the first Reconstruction, told me. “But they are certainly doing things that hearken back to a very dark period in US history.”

This unravelling has intensified since John Roberts became Chief Justice in 2005. Under Roberts, the court majority has barred K-12 school districts from considering race even in voluntary desegregation plans and banned the use of race in college admissions. In the 2013 Shelby County decision, the majority effectively eliminated the Voting Rights Act’s requirement for jurisdictions with a history of racial discrimination to receive pre-clearance from the federal government for voting changes. In oral arguments last week, the majority seemed poised to topple the VRA’s remaining pillar by invalidating the provision that bars voting rules that have the effect of discriminating on the basis of race.

That voting rights case, which focuses on Louisiana’s congressional district map, will offer another marker of this majority’s willingness to overturn long-settled law and upend the longstanding approaches many institutions have adopted to address racial equity. If the court weakens the VRA again, experts predict Republican-controlled states across the South will redraw congressional maps to eliminate between 12 and 20 minority representatives in the US House. That would mean eliminating, in one blow, at least one in every ten minorities in that chamber, and potentially many more.

Yet minorities are preponderantly driving the population growth in those states. In Texas, according to calculations done for me by the Equity Research Institute at the University of Southern California, non-Whites have accounted for 92 per cent of the state’s population increase since 2010 — and yet they will almost certainly lose representation if the court further enfeebles the VRA.

The one big area of civil rights law the Roberts court hasn’t yet significantly reconsidered is in employment. But even there, conservative legal groups and the Trump Administration are citing the court’s 2023 decision on college admissions to pressure private employers to drop diversity, equity and inclusion programmes, and to challenge the use of “disparate impact” analysis that identifies employment practices that discriminate against minorities or women.

Sinha and other observers point to many similarities between the court’s actions today and during the first Reconstruction. Then, as now, the Supreme Court’s decisions nullifying civil rights protections often overturned lower court rulings affirming them. In both instances, she notes, the Supreme Court not only reacted to changes in the political environment, but led them. For example, after the Supreme Court in 1883 struck down the federal Civil Rights Act of 1875 as unconstitutional, southern states responded with laws imposing segregation; similarly, after Shelby County, Republican-controlled states responded with a wave of statutes making it harder to vote.

In both eras, the court also allowed race to be used as a sword, but not as a shield. While the 19th-century court stopped Congress from using race to protect the former slaves, Sinha notes it upheld the use of race to exclude all immigrants from China. Likewise, even as the Roberts court has repeatedly barred the consideration of race to benefit minorities, in an emergency order it recently allowed ICE to use racial profiling in immigration sweeps.

Most importantly, she notes, both courts sought to redefine the meaning of the 14th Amendment, the cornerstone Reconstruction-era addition to the Constitution, which sought equal rights for freed slaves by guaranteeing all Americans “equal protection” and “due process” under the law. The 19th-century court twisted the amendment into a mechanism to protect corporations against government regulation. The Roberts court has repeatedly interpreted it to strike down civil rights protections as discriminating against White people.

In one respect, today’s Supreme Court counter-revolution is even more sweeping. The 19th-century court’s decisions subjugated an African-American community that remained only about one-eighth of the nation’s population in 1880, overwhelmingly concentrated in the former slave states. Today’s court is reversing inclusion policies at a moment when people of colour already comprise a majority of America’s under-18 population and a majority of high school graduates, and are on track to become a majority of the entire population in the 2040s.

And yet on the key measures, this growing minority population remains substantially underrepresented in the upper echelons of American society. Although Black and Hispanic students now account for nearly two fifths of the total postsecondary student body, they still hold only about one fifth of the seats at the 500 most selective schools, according to the Georgetown Centre on Education and the Workforce. Ben Zipperer, a senior economist at the Economic Policy Institute, has calculated for me that Black and Latino people represent only a little over one sixth of workers whose wages put them in the top quintile of all wage earners, though they comprise nearly one third of all workers. A Harvard Law School analysis has found that Black, Latino and Asian Americans hold less than one fourth of upper management jobs across the 100 largest companies in the S&P 500, far below their combined share of the workforce.

The court’s decisions are making it much more likely these disparities will endure. Maybe the best way to understand the implications of the court’s actions is to picture US life as a vast skyscraper: although people of colour are filling more of the lower and middle floors, the Supreme Court is making it more likely that the very highest stops on the elevator — the penthouse and C-suite of American life — remain predominantly White.

“This is not striking a deal with the White South to allow them to lock out Black southerners from political power and economic opportunity; this is locking out the next America,” says Manuel Pastor, director of the Equity Research Institute.

Apart from the Earl Warren era (1953 to 1969), the Supreme Court has rarely led on race. But most scholars consider the 19th-century Reconstruction court, mostly led by pedestrian Chief Justice Morrison Waite, an especially low moment in judicial history. Although far more skilled, Roberts is steering today’s court majority through a dismantling of America’s second racial reconstruction in a manner that inescapably echoes Waite’s role in unravelling the first.

• Ronald Brownstein is a Bloomberg Opinion columnist covering politics and policy. He is a CNN analyst and the author or editor of seven books