The 63-year-old conservative commentator now joins Bryan Fischer, Scott Lively, Tony Perkins and the Westboro Baptist Church's Fred Phelps on the list created by the SPLC, one of the oldest civil rights organizations.
"Carson’s own story as an 'up by the bootstraps' black man reared in poverty translated into an inspiring, magnetic narrative that captured media attention," SPLC's profile notes. "Soon he was appearing as the keynoter at a rash of right-wing and hate group gatherings, linking gays with pedophiles, comparing the U.S. to Nazi Germany and endorsing biblical economic practices for 21st century America."
The profile also points out that Carson "has coyly declined to say whether he would run [for U.S. president] as a Republican or on a third-party ticket, but media interviews suggest that he is increasingly willing to run on some ticket."
The news is not particularly surprising given Carson's history. At Congressman Steve King's Iowa Freedom Summit last month, he made headlines after hinting that anti-LGBT bakery owners "might put poison" in cakes they prepared for same-sex couples.
In his 2012 book, America the Beautiful: Rediscovering What Made This Nation Great, he argued that attempts to "redefine marriage" would bring about a "disastrous ending" for the U.S. that would mirror "the dramatic fall of the Roman Empire," according to Media Matters.
In less LGBT-specific news, he also slammed Obamacare as "really the worst thing that has happened in this nation since slavery. And…in a way, it is slavery.”
UPDATE: Carson called the SPLC designation "projectionist," telling Breitbart:
When embracing traditional Christian values is equated to hatred, we are approaching the stage where wrong is called right and right is called wrong. It is important for us to once again advocate true tolerance. That means being respectful of those with whom we disagree and allowing people to live according to their values without harassment.