Dr. Benjamin Carson, who has come under heavy criticism in recent days for comparing marriage equality supporters to advocates of bestiality and pedophilia, wrote in his 2012 book that marriage equality “is a slippery slope with a disastrous ending, as witnessed in the dramatic fall of the Roman Empire.”

In a March 26 appearance on Fox News (where he has recently become a regular fixture), Carson said, “Marriage is between a man and a woman. No group, be they gays, be they NAMBLA, be they people who believe in bestiality, it doesn't matter what they are. They don't get to change the definition.” He added that his argument is “not something against gays,” but “against anybody who wants to come along and change the fundamental definitions of pillars of society. It has significant ramifications.”

Carson also pushed anti-marriage equality views in his most recent book. Carson warned in America the Beautiful that attempts to “redefine marriage” could lead to a “disastrous ending” for America on par with the fall of the Roman Empire. He explained that his opposition is “a logical and reasoned view” because marriage between a man and a woman benefits the “family structure and the propagation of humankind. ... God obviously knew what he was doing when he ordained the traditional family, and we should not denigrate it in order to uplift some alternative.”

Carson added that he has “no problem whatsoever with allowing gay people to live as they please, as long as they don't try to impose their lifestyle on everyone else” and would support “gays or non-gays” having a legally binding relationship “that helps with the adjudication of property rights and other legal matters.” Carson then compared this legal relationship to allowing Muslims to privately practice religion: “Likewise, I have no problem with Muslims or other religious groups who want to practice their religion in their homes, which may be vastly different from traditional Judeo-Christian religion, as long as they don't try to impose that on others or violate our laws.”

From Carson's book America the Beautiful: Rediscovering What Made This Nation Great:

As a Bible-believing Christian, you might imagine that I would not be a proponent of gay marriage. I believe God loves homosexuals as much as he loves everyone, but if we can redefine marriage as between two men or two women or any other way based on social pressures as opposed to between a man and a woman, we will continue to redefine it in any way that we wish, which is a slippery slope with a disastrous ending, as witnessed in the dramatic fall of the Roman Empire. I don't believe this to be a political view, but rather a logical and reasoned view with long-term benefits to family structure and the propagation of humankind. When children grow up in an environment with loving parents who provide security, they are free to be happy and playful and eager to learn. God obviously knew what he was doing when he ordained the traditional family, and we should not denigrate it in order to uplift some alternative.

However, I have no problem whatsoever with allowing gay people to live as they please, as long as they don't try to impose their lifestyle on everyone else. Marriage is a very sacred institution and should not be degraded by allowing every other type of relationship to be made equivalent to it. If gays or non-gays wish to have some type of legal binding relationship that helps with the adjudication of property rights and other legal matters, I certainly have no problem with that, but to equate that with marriage is going further than necessary. Likewise, I have no problem with Muslims or other religious groups who want to practice their religion in their homes, which may be vastly different from traditional Judeo-Christian religion, as long as they don't try to impose that on others or violate our laws. I could go on with other examples for quite some time, but I hope I have conveyed the wonderful freedom we enjoy as citizens of a government that protects the right to privacy. [America the Beautiful: Rediscovering What Made This Nation Great, pg.182, via Kindle edition]

Carson's comments on Hannity sparked widespread criticism, including from colleagues and students at Johns Hopkins, where Carson is a professor. The co-director of Hopkins' Program for the Study of Women, Gender, and Sexuality called Carson's remarks “reactionary and rancid,” while LGBT leaders at the school found the comments “hurtful.”

Students from the graduating class at the Johns Hopkins School of Medicine are calling for Carson to be replaced as the scheduled 2013 commencement speaker at the school.