On Monday morning, the Pasadena, Texas, City Council was debating a tax collection contract when Republican Mayor Johnny Isbell moved to take a vote. Democratic Councilman Cody Ray Wheeler objected, noting he hadn’t “had an opportunity to speak yet.” Isbell, who is white, replied to Wheeler, who is Hispanic: “Well, you better speak up, boy.” When Wheeler expressed offense and insisted that he be treated with more respect as a member of the council, Isbell responded: “Well, act like it.”

When Wheeler finished his statement, Isbell backpedaled, telling Wheeler: “You’re right, council member, and that was a slip of the tongue on the ‘boy.’ ”

Isbell’s “slip of the tongue” at this public meeting wasn’t just a shocking one-off racist incident. The Pasadena mayor was the driving force behind a 2013 redistricting scheme found to intentionally discriminate against Hispanic voters. Shortly after the Supreme Court gutted the Voting Rights Act that year, Isbell concocted a plan that would deprive Hispanic voters of the ability to elect a majority of City Council seats—something they were finally poised to do thanks to demographic changes. The mayor proposed replacing the current system of eight single-member seats with six single-member and two at-large seats. The new system, placed on the ballot as Proposition 1, eliminated a majority Latino district. Pasadena voters narrowly approved it.

In January, Chief U.S. District Judge Lee H. Rosenthal issued a scathing ruling after conducting a seven-day trial that featured 16 witnesses and 468 exhibits. In a 113-page decision, Rosenthal concluded that Proposition 1 was designed to dilute minority voting strength in violation of the Voting Rights Act and the Equal Protection Clause. As a result, Rosenthal struck down the new system and placed Pasadena back under federal supervision, requiring federal approval of all future voting-related changes. Her decision contained devastating criticism of Isbell, who has long been accused of favoring Pasadena’s Anglo population, neglecting its Latino communities, and exhibiting racism. (Isbell once publicly alleged that 70 percent of Pasadena’s Hispanic population were “illegal aliens,” which is, of course, false.)

Rosenthal found that Isbell devised Proposition 1 to halt an “imminent power shift away from the Mayor and the Anglo majority.” She also found that Isbell had, indeed, neglected the majority Hispanic parts of the city while pouring money into its majority Anglo communities. But this money came with strings: Isbell distributed grants on the condition that their recipients would campaign in favor of his redistricting scheme.

According to Rosenthal, Isbell also improperly used campaign funds, city resources, and city employees to campaign for Proposition 1—and to turn out votes for the measure on Election Day. At trial, Pasadena’s then director of community relations (who was also a good friend of Isbell’s) admitted under oath that he had illegally used city employees and resources to campaign for Proposition 1 during business hours. He later resigned. Isbell testified under oath, too; Rosenthal found that his testimony was “not credible.”

Isbell is now appealing Rosenthal’s decision to the 5th Circuit U.S. Court of Appeals. He insists that Proposition 1 was not racially discriminatory and that his redistricting scheme was, at worst, designed to disenfranchise Democrats, not minorities. To succeed, he will need to convince the court that he did not overhaul a perfectly functional electoral system—and dilute the votes of minorities—with the intent to discriminate against Hispanics. His opponents, though, will probably find a way to call the court’s attention to Monday’s “slip of the tongue.” It seems likely that such an outwardly racist remark will make it that much harder for Isbell to persuade the 5th Circuit that he’s in the right.

*Correction, March 28, 2017: This post originally misstated Rosenthal’s gender.