The following op-ed, The lessons of Dred Scott, co-written by HLS Professor Charles Ogletree and Johanna Wald, director of strategic planning at the Charles Hamilton Houston Institute, was published in The Boston Globe on April 5, 2007.

One hundred fifty years ago — on March 6, 1857 — the Supreme Court issued a landmark decision that haunts us today. In Dred Scott v. Sandford the court found all “negroes,” even free ones, exempt from the rights, privileges, and immunities afforded to US citizens by the Constitution. Chief Justice Roger Taney, writing for the majority, concluded that blacks “had no rights which the white man was bound to respect.”

Today, we view the ruling as a travesty and stain on our history. At the time, the decision, though hardly universally repudiated, did stun and anger many people. It mobilized abolitionists and accelerated the march toward civil war. We can now point to a series of legal decisions and laws affirming the nation’s commitment to basic rights for all: the passage of the 14th Amendment in 1868 granted blacks equal protection under the law, the Supreme Court’s 1954 Brown v. Board of Education decision repudiated the doctrine of “separate but equal” schools, the Civil Rights Act of 1964 outlawed discrimination based on race, color, religion, sex, or national origin, and the Voting Rights Act of 1965 enabled African-Americans across the nation to exercise the right to vote.

However, a careful read of the nation’s history reveals a pattern more accurately described as an ebb and flow than a steady current drifting toward full equality. No sooner do we grant rights and privileges to certain groups than we begin the process of revoking and curbing them. Yes, blacks were granted the right to vote in 1868. Then, poll taxes and intimidation kept most from exercising that right, particularly in the South, before 1964. Today, one in 12 blacks has been stripped of the right to vote because of laws denying this basic privilege to people convicted of a felony. Increasing voter identification requirements recently passed in several states will likely further suppress the votes cast by people of color there.

Yes, Brown legally abolished the odious “separate but equal” schools. However, since the 1980s, schools for Latino and black students have grown more segregated as federal courts chipped away at the legal foundation supporting desegregation. This spring, the Supreme Court may even outlaw locally crafted voluntary measures designed to prevent segregation, rending the promise of the Brown ruling a fatal blow.

The recent raid on a leather factory in New Bedford underscores the lack of even basic legal protections provided to the nation’s estimated 12 million undocumented immigrants. More than 300 workers — most women with young children at home — were detained, handcuffed, and arrested. Department of Homeland Security officers sent many detainees across the country before they could make provisions to care for their children, setting off a humanitarian crisis. During a community meeting, one teenage girl whose mother had been detained in the raid flashed her American passport and tearfully proclaimed: “I am an American. How can they do this to me?”

Her question conveys the human anguish caused by denying rights and privileges to those who live within our borders. Each new restriction that we impose is always rationalized as necessary — for “national security,” for stemming illegal immigration, for punishing criminals, for rooting out “voter fraud” or for preserving parents’ rights to choose their children’s schools. But we must remember that 150 years ago, the Dred Scott decision was widely justified as an effort to settle the divisive slavery question, to fend off the prospect of civil war, and to strengthen the powers of the federal government.

The questions at the heart of the Dred Scott case — about citizenship, belonging, and participation — remain unresolved. As we stand at a crossroads, challenged by threats abroad and within, we, like the Supreme Court in 1857, risk being blinded by our own cultural assumptions. These threaten the admirable gains we have made during the past century and a half. We must not lose sight of the context that not only enabled the Dred Scott decision in 1857, but led far too many members of the public to view the decision as sensible and right.

The civil rights era demonstrated that we are a nation strong enough to withstand harsh self-examination and to correct our mistakes. With the lessons learned from Dred Scott, we must invoke that spirit of reflection now and reawaken the America that embraces change, diversity, and progress.