The Congressional Hispanic Caucus called on the Heritage Foundation Friday to renounce the writings of Jason Richwine, a former Heritage employee and one of the authors of the group’s recent immigration report.

Richwine resigned this week amid a scandal over a doctoral thesis that suggested Latinos and other immigrants were not as smart as white Americans, according to news reports.

“Though the CHC welcomes Jason Richwine’s resignation, it is still very disheartening that the Heritage Foundation did not renounce his research and the ridiculous report on immigration that he co-authored,” CHC Chairman Rubén Hinojosa, D-Texas, said in a statement.

“We cannot afford the consequences of this man’s bigotry and ignorance to ripple through productive, bipartisan talks toward immigration reform,” Hinojosa continued. “I applaud those in the media and the community who stepped up and did what the Heritage Foundation was unwilling to do — call out unmistakable racism. Until the Heritage Foundation is willing to denounce Richwine’s work, shame on them and shame on those who support and fund them.”

Slate’s Dave Weigel reported Friday afternoon that Richwine had stepped down from his post at Heritage. Earlier in the week, news outlets reported that he had written a doctoral thesis at Harvard University which stated that the “average IQ of immigrants in the United States is substantially lower than that of the white native population.” He went on to suggest that the U.S. should focus on selecting “high-IQ immigrants” for entry, and he wrote: “No one knows whether Hispanics will ever reach IQ parity with whites, but the prediction that new Hispanic immigrants will have low-IQ children and grandchildren is difficult to argue against.”

Richwine co-authored a Heritage report on immigration that found that the cost of allowing an estimated 11 million immigrants to apply for legal status would reach $6.3 trillion over 50 years. The work was widely panned on both sides of the aisle, with the libertarian Cato Institute, Americans For Tax Reform President Grover Norquist, and House Budget Chairman Paul D. Ryan, R-Wis., lambasting it as flawed in its analysis.

Correction: This post has been updated to reflect the correct amount the Heritage report estimates the immigration overhaul will cost.