As unlikely as it seems in light of the Supreme Court’s recent civil rights decisions, the late Justice Thurgood Marshall and Justice Clarence Thomas do have a few things in common. Most obviously, they are the only two African Americans to have served as justices on the U.S. Supreme Court—Justice Marshall from 1967 to 1991 and Justice Thomas, who replaced him, from 1991 to the present. Both men are also known for their fiery dissents.

Yet the two jurists could not present a clearer contrast in their approaches to interpreting the law. Justice Thomas’s “originalist” philosophy calls for interpreting the Constitution by looking to the words in the document. Justice Thomas said in a 2005 dissent that “the Constitution’s original meaning” should trump previous decisions if those decisions are “wholly divorced from the text, history, and structure of our founding document.” Justice Marshall, on the other hand, referred to the Constitution as a “living document” and famously described his judicial philosophy as “you do what you think is right and let the law catch up.”

As a lawyer for the National Association for the Advancement of Colored People, or NAACP, Justice Marshall argued and won many cases before the highest court in the land. Justice Marshall served on the Court for 24 years and amassed a record as a strong protector of individual rights. As a Supreme Court justice, he worked to shore up the legal and political victories he won as a civil rights lawyer.

Before becoming a judge, Justice Thomas worked at the U.S. Equal Employment Opportunity Commission during the Reagan administration, where he limited the use of class-action lawsuits to enforce workplace-discrimination laws. Since his appointment to the High Court, Justice Thomas has established a reputation as arguably its most conservative justice, and he has consistently ruled in favor of narrowly interpreting civil rights protections. His positions in the Court’s recent civil rights cases demonstrate that he may be more opposed than any other justice to the government’s consideration of race in programs that help African Americans.

On June 25, 2013, Justice Thomas voted with the majority in Shelby County v. Holder to strike down the Voting Rights Act’s system for determining which states must “pre-clear” any changes to voting by state and local governments due to a history of discrimination in voting. In a 5-4 vote, the majority ruled that the Voting Rights Act’s system for deciding which governments were subject to the preclearance requirement was “unconstitutional in light of current conditions.”

The Court faulted Congress for continuing to use a jurisdiction’s history of voting discrimination prior and up to 1965, when the Voting Rights Act was passed, to determine the application of the preclearance rule. In his opinion for the Court, Chief Justice John G. Roberts Jr. said the pre-1965 history of discrimination is no longer relevant. “Today the Nation is no longer divided along those lines,” he wrote. The Court said Congress’s legislative record of continuing voting discrimination in these jurisdictions—amassed before the 2006 reauthorization of the act—did not demonstrate “anything approaching the … discrimination that clearly distinguished the covered jurisdictions from the rest of the Nation in 1965.” Justice Roberts’s opinion relied on a new doctrine of “equal sovereignty,” which apparently requires the federal government to treat the states equally.

Justice Thomas and the other conservative justices seem to believe that racism in voting is over, or at least that Southern states have made enough progress that the preapproval requirement is no longer justified. But the alarming increase in voter ID laws and other discriminatory voting-suppression measures show that our nation has much further to go.

Justice Marshall wrote an opinion for the Court in 1986 that rejected similar arguments that the Voting Rights Act’s preclearance system was outdated. He said that any concerns about violating state sovereignty were “necessarily overridden” by Congress’s power to enforce the post-Civil War amendments to the Constitution, which were “specifically designed as an expansion of federal power and an intrusion on state sovereignty.” The Court in 1986 found “no reason … to disturb Congress’ considered judgment that banning electoral changes that have a discriminatory impact is an effective method” of battling voting discrimination.

Justice Marshall also voted to sustain government efforts to ensure equality in the face of constitutional challenges. Having fought the legal battles to bring down Jim Crow, Justice Marshall was aware that “desegregation is not and was not ever expected to be an easy task.” He believed that affirmative measures, such as busing students to ensure diversity in schools, were necessary to live up to the promise of Brown v. Board of Education. In a 1974 dissent, Justice Marshall warned that political resistance should not justify the end of a federal judge’s plan to desegregate Detroit-area schools: “In the short run, it may be the easier course to allow our great metropolitan areas to be divided up into two cities—one white, the other black—but it is a course, I predict, our people will ultimately regret.”

In the June 24, 2013, opinion in Fisher v. University of Texas, coming decades after Justice Marshall’s tenure, the Court seemed to express concerns about whether a public university using race as one of many factors in admissions decisions was justified by the “educational benefits that flow from a diverse student body.” The Court overturned a lower court ruling that upheld the University of Texas’s admission program because it did not ask “whether a university could achieve sufficient diversity without using racial classifications.” The lower court had merely asked whether the university’s decision was made “in good faith.”

Justice Thomas would have gone further and explicitly banned the consideration of race in public college admissions under the Equal Protection Clause. He went so far as to compare the arguments in favor of affirmative action to proffered justifications for slavery and arguments “advanced in support of racial segregation” in Brown v. Board of Education, a case that Justice Marshall argued for the NAACP. Justice Thomas noted that Brown rejected segregationists’ arguments that a separate education “provided more leadership opportunities for blacks.” He wrote, “No court today would accept the suggestion that segregation is permissible because historically black colleges produced Booker T. Washington, Thurgood Marshall, Martin Luther King, Jr., and other prominent leaders.”

In his remarkable concurring opinion, Justice Thomas invokes Justice Marshall’s name, along with his arguments as a lawyer in Brown, to assert that affirmative action violates the constitutional rights of white college applicants. If there was any doubt before this concurrence, it is now clear that the second black justice is doing everything in his power to undo nearly everything that the first black justice accomplished—as a lawyer and a judge—to ensure a more equal society.

Billy Corriher is the Associate Director of Research for Legal Progress at the Center for American Progress.