On Tuesday, Supreme Court Justice Ketanji Brown Jackson made headlines and drew praise by invoking the 13th, 14th and 15th amendments to the Constitution — the Reconstruction Amendments — during oral arguments over Alabama’s alleged violation of the Voting Rights Act.

Drawing on 19th-century sources, including speeches and congressional committee reports, Jackson explained that, when she examined “what the framers and the founders thought,” it became evident that the authors of the 14th Amendment’s equal protection clause knew that securing racial equality did not necessarily mean legislating in a race-blind way. Alabama’s new congressional map, in short, did not match the intent of those who devised the amendment.

Jackson’s move surprised court watchers because originalism is usually associated with the contemporary conservative legal movement — an expanded Second Amendment, the rollback of women’s reproductive rights and more. One writer referred to her questioning as a rare example of “progressive originalism” — trying to divine the Constitution’s original meaning from the historical record to guide liberal policymaking and jurisprudence.

But in reality, such a version of originalism isn’t new. Instead, Jackson’s constitutional interpretation joins a storied tradition in the struggle for equal rights. First abolitionists and later the “Radical Republicans” who shaped Reconstruction — the very people whose ideas Jackson cited — tied their movement to the founders’ supposed original intentions. By resurrecting this tradition, Jackson isn’t simply co-opting a conservative legal philosophy. She’s also giving the Democratic Party a road map for effective constitutional politics.

Maybe the most enduring quotations about the Constitution’s relationship with slavery come from William Lloyd Garrison, who called the document a “covenant with death” and an “agreement with hell.” But while some abolitionists like Garrison scorned the Constitution, many others knew that they could not afford to cede the legacy of the founding to enslavers. The early 19th century was, according to historian Eric Foner, a time when people “cared deeply about constitutional interpretation.” Whatever flaws the founders had, these abolitionists understood that if their goal was to build power, they had to connect their efforts with the founding.