In the wake of a highly-criticized study on immigration released by the conservative think tank Heritage Foundation, Rush Limbaugh has come out in defense of one of the study’s co-authors who has been accused of racism.

In 2009, co-author of the study Jason Richwine wrote that immigrant Hispanics have inherently lower IQs than ”the white native population,” going on to wonder if “Hispanics will ever reach IQ parity with whites.” The discovery of the dissertation was a huge blow to Heritage, forcing the think tank to release a statement saying that Richwine’s previous writings “do not reflect the positions of The Heritage Foundation.”

On his radio show this Thursday, Limbaugh said that Richwine’s previous writings “are something that we ought to consider when analyzing  and coming up with immigration policies.”

“You’re not supposed to bring that kind of stuff up. You’re just not supposed to talk about it — that’s not politically correct,” Limbaugh said sarcastically. “Even if it’s true, you’re not supposed to bring it up.”

Listen to Limbaugh’s comments in the video below.