This is about as silly a use of the power the government has arrogated to itself and decided to use more aggressively since 9/11 as I've heard of. Sebastian Horsley is a British upper-class toff who has written a book about his life as a wastrel -- drugs, alcohol, prostitutes, rehab, getting sober but still being depraved -- called "Dandy in the Underworld." He was coming to the U.S. for a book tour, but was turned back by ICE for "moral turpitude" -- arriving in New York, whose former governor had just resigned over a prostitute scandal and whose current governor has admitted both he and his wife had affairs and he took drugs when he was younger.
Turns out Horsley, who is viewed as more odd and maybe absurd than criminal back home, had a drug conviction in the UK 25 years ago. According to the U.S. customs people, it doesn't matter that he's been to rehab and is drug-free now. That old conviction is enough.
These laws are arbitrarily enforced -- Horsley has been to the U.S. several times before without complication -- but somehow he got an a watch list for this time. Maybe it was the added notoriety of the book. But the laws on visas for those accused or moral turpitude -- vague and arbitrary and they tend to be applied to gays more often than others -- should simply be eliminated. They make the United States look absurd because, in this instance, it is absurd.