Former NBA great Kareem Abdul-Jabbar comes out swinging against Dr. Ben Carson, writing that Carson would be a terrible president and an “unmitigated disaster” for black Americans.

In a Wednesday Time op-ed, Abdul-Jabbar first concedes that Carson “is good for African Americans in that he is a deeply moral man who has done much good as a physician and now wants to upsize his good-doing on a national and global scale” and acknowledges that Carson’s “success story is the stuff the American Dream is made of and is motivation for others to follow his path.”

“His accomplishments as a medical doctor are admirable and serve as an inspiration for young black men and women seeking a career in science. His measured, even groggy demeanor, commands attention and respect,” he writes. “Had he decided to dedicate his post-retirement life to promoting STEM education across the country, he would have been a model for the American ideal that anything is possible.”

But God forbid such an accomplished man run for president as a conservative and potentially get black voters to consider voting for the GOP and think about how failed left-wing policies have impoverished their communities and not given them opportunities to move up the economic ladder. Abdul-Jabbar writes that Carson “chose to run for president of the U.S., and that’s bad for African-Americans.”

Abdul-Jabbar’s op-ed was published on the day a new Quinnipiac poll was released that found Carson with a 10-point lead over Hillary Clinton largely because he gets 19% of the black vote compared to 73% for Clinton. The poll led the African-American publication The Grio to declare that Carson “could beat the Democratic frontrunner Hillary Clinton in a general election, and it might just be with the help of African-American voters.”Carson even leads Clinton among women voters (45%-44%).

Though Breitbart News Editor-at-Large John Nolte exposed Abdul-Jabbar’s past oppressive views toward women, which prompted Abdul-Jabbar to directly respond and declare that he no longer held those views, Abdul-Jabbar writes that Carson’s “repressive, muddled and pious policies and opinions often run against our Constitution—but his questionable proposals will likely, thankfully, be doomed by his lack of political expertise.”

Writing without any sense of irony regarding President Barack Obama’s many instances of leading from behind, Jabbar writes that a Carson presidency “would definitely not be good for African Americans to have a president who flounders helplessly in office because it would perpetuate the stereotype that blacks can’t be effective CEOs, quarterbacks and leaders.”

Abdul-Jabbar also takes issue with Carson’s belief that “sexual orientation is a choice” and skepticism about global warming. He also says that Carson’s “judgment as a man of science was also compromised last February when he blamed an outbreak of measles on illegal immigrants from South and Central America” and accuses Carson of perpetuating “the black stereotype of someone who’s too confused or frightened by all that complicated science so he or she ignores it, clinging to superstitions or religion.”

“Obviously, white politicians have been making the same buffoonish claims, but they aren’t representative of a minority struggling to achieve equality,” Abdul-Jabbar writes.

He also takes Carson’s comments about Democrats manipulating blacks and taking their votes for granted out of context, claiming that Carson has referred to “black Americans as unable to think for themselves because they disagree with him.” Because Carson opposes Obamacare, Abdul-Jabbar says that “a Carson presidency would also be a direct attack on the health of African-Americans.” Responding to Carson’s comparison of Obamacare to slavery, Abdul-Jabbar says that “poverty is the form of slavery that is most insidious in America, and it is perpetuated by institutional racism, which Ben Carson seems to deny exists.

“These are the times when all Americans need a champion willing to fight hard to fix the problems that affect people from all walks of life, not deny or ignore them,” Abdul-Jabbar opines. “Ben Carson is not that champion.”