A version of this story was originally posted on NBC Latino. Another day, another series of head-scratching comments surfacing from Jason Richwine, co-author of a controversial immigration study, which sought to calculate the cost of undocumented immigrants becoming citizens with immigration reform legislation pending. In three YouTube clips added Thursday by the American Enterprise Institute, a conservative think-tank, Richwine pours water on the idea that all races and ethnicities are equally likely to assimilate saying that blacks, Native Americans and Mexicans have shown an inability to do so. Unlike the Irish and Sicilians who he says assimilated, some groups have no prospect of that happening, he says. “We have blacks, we have American Indians and even early Mexican Americans who have been living in the country for a long time and have not assimilated to the cultural mainstream as typified by white Americans,” he says. Richwine goes on to say black and white culture has diverged in the last 50 years, Native Americans are still on reservations and Mexicans who have been here for a long time also can not assimilate. “They’ve been around since the Mexican-American war,” he says. “They’ve been here ever since and I don’t think that they have been defined as white, certainly not by Europeans and really not by themselves except in the cases where they’re trying to distinguish themselves from being black.” Richwine goes on to propose a “thought experiment.” “Imagine if early immigrants in the 20th century — the Italians, the Pols, the Jews, the Irish. Imagine if we replaced all of them with, say, Australian-aborigines, Pakistanis and Cambodians. Imagine if they were the immigrants in the early part of the 20th century. Can we really say with any kind of rational argument that they today would be absolutely indistinguishable from the white majority?” Richwine adds that while he doesn’t see race as insurmountable, it is a larger barrier today, “simply because they are not from Europe.” In a blog post The Heritage Foundation sought to separate itself from Richwine’s comments and a 2009 disseration where he said Hispanic immigrants have low-IQ’s and are destined to have children and grandchildren with low-IQ’s as well. They said the dissertation was “not a work product of The Heritage Foundation” and “its findings do not reflect the positions of The Heritage Foundation or the conclusions of our study on the cost of amnesty to U.S. taxpayers, as race and ethnicity are not part of Heritage immigration policy recommendations. “We welcome a rigorous, fact-based debate on the data, methodology, and conclusions of the Heritage study on the cost of amnesty,” wrote Mike Gonzalez, vice president of communications, at The Heritage Foundation. “Instead, some have pointed to a Harvard dissertation written by Dr. Jason Richwine. Dr. Richwine did not shape the methodology or the policy recommendations in the Heritage paper; he provided quantitative support to lead author Robert Rector. The dissertation was written while Dr. Richwine was a student at Harvard, supervised and approved by a committee of respected scholars.” The National Council of La Raza, which blasted Richwine’s dissertation comments as ”unspeakable” were further angered but mostly just shocked about the new videos. Lisa Navarette, advisor to the NCLR president said she couldn’t believe Harvard gave him a Phd. “This gentleman’s PhD dissertation shows that when you scratch the surface of extreme immigration opposition you find a disturbing and troubling history with racism, a belief in eugenics,” she said. “It’s just troubling and disturbing. It’s bigotry disguised as science.” Online humor and social commentary site Latino Rebels called Richwine “racist” for his views and many on Twitter piled on. Glad to see they’re naming and shaming this Jason Richwine character. These types of people need to be run out of the conservative movement. — Matt Dabrowski (@MattDabrowski) May 9, 2013 Hector Cordero, posted the conclusion to Richwine’s dissertation which says “today’s immigrants are not as intelligent on average as white natives.” Richwine’s beliefs have only added to the anger surrounding the Heritage Foundation study on the cost of a path to citizenship included in the immigration reform bill, which they calculated to be $6.3 trillion, but conservatives blasted as incorrectly calculated. Now groups like the Center for Community Change have called for Heritage president and former senator, Jim DeMint to resign. “No one should be surprised by the results of the Heritage Foundation’s “economic study” about the cost of immigration reform. After all, its president, Jim DeMint, is someone who has a history of unabashed opposition to immigration reform,” the statement read. “We cannot stand by and allow our country’s ugly history of racism and injustice to repeat itself.”