In 1978, gifted writer Ken Auletta profiled for Esquire the pugnacious attorney Roy Cohn whom he called the “personification of evil.” Cohn died in 1986 discredited and disbarred. Donald Trump was a Cohn client and close friend. He called Cohn his mentor. Ken Auletta tells Jim Zirin some of the dirty tricks Trump learned at the feet of the master of the smear.