The man behind Thursday’s Supreme Court decision striking down affirmative action in higher education admissions is nowhere near finished. Next on his target list: rules from the state of California and the Securities and Exchange Commission requiring diversity quotas for corporate boards.

Edward Blum, a conservative legal strategist whose Students for Fair Admissions nonprofit was plaintiff in both cases before the court, has been waging a one-man crusade against racial preferences for more than 30 years. He’s lost some cases along the way and won others, but Thursday’s victory was by far the most consequential.

“The opinion issued today by the United States Supreme Court marks the beginning of the restoration of the colorblind legal covenant that binds together our multi-racial, multi-ethnic nation,” Mr. Blum said in a statement after the decision was announced. “The polarizing, stigmatizing and unfair jurisprudence that allowed colleges and universities to use a student’s race and ethnicity as a factor to admit or reject them has been overruled. These discriminatory admission practices undermined the integrity of our country’s civil rights laws.”

Mr. Blum has been personally involved in six cases that have come before the Supreme Court, three of which involved race-based admissions at universities. Two previous efforts challenging them at the University of Texas were unsuccessful. The two Students cases decided Thursday mark his first major victory on the topic.

While not a lawyer himself, the former stockbroker has connected plaintiffs who feel they have been discriminated against with legal teams funded by conservative donors to bring cases solely for the purpose of setting legal precedents. For his efforts, Mr. Blum has been assailed as a racist by left-wing ideologues and as a patriot by conservatives. 

Before Thursday, his biggest case was a challenge to the widespread practice of gerrymandering congressional districts to favor one race over another known as Shelby County v. Holder. In it, Mr. Blum helped an Alabama county sue the federal government over a requirement in the 1965 Voting Rights Act that any changes to voting procedures by the states be pre-approved by the Department of Justice to ensure that they don’t suppress the votes of minority voters.

After hearing arguments in the case and by a 5-4 ruling, the Supreme Court in 2013 struck down the relevant section of the Voting Rights Act — Section 5 — by invalidating the formula used to determine which states must obtain the so-called pre-clearance required by the Act.

Mr. Blum’s next target is recent moves by state governments and federal regulators that require companies to use racial quotas when appointing people to their boards of directors. Under the aegis of the Alliance for Fair Board Recruitment, Mr. Blum is suing the SEC over a rule requiring companies listed on the Nasdaq to have at least one female board member and one who self-identifies as Black, Latino, Asian, Native American, or Alaska Native, two or more races or ethnicities, or as LGBT. The case is now pending before the Fifth Circuit.

“It is not only investors who will suffer if Nasdaq’s virtue signaling rule is allowed to take effect,” the group says. “AFFBR has members who, because of their race, sex, and sexual orientation are forced to compete on an uneven playing field because of Nasdaq’s quota requirements.”

Also in his crosshairs is a similar rule passed by California in 2020 requiring companies based in that state to have a minimum number of directors from what the state considers “underrepresented groups.” A federal court ruled earlier this year, in Alliance for Fair Board Recruitment v. Weber, that the rule violates the Constitution’s Equal Protection Clause, the same clause cited by the Supreme Court in Thursday’s higher education decision.

The 71-year-old Mr. Blum seems disinclined to slow down his efforts against racial discrimination. In press interviews, he has said his quest is motivated by a desire to uphold the tenets of the 1964 Civil Rights Act, which he believes explicitly forbid treating Americans differently because of their race. The spirit of the law, he says, seems to have been lost in the intervening years.

“I would like to see jurisprudence issued in which racial classifications are considered off-limits, except under the most extraordinary circumstances,” he told the Financial Times in a recent interview. “Police seeking to infiltrate a race-based drug gang could hire someone of the same background, but that’s about it.”