Cohn was allegedly involved in the construction of Trump Tower. Trump Tower was to be built with concrete, however, at the time there was a city-wide Teamster strike and most unions in Manhattan were controlled by or had ties to organized crime. Cohn had represented mobsters in the past like Carmine Galante and Anthony Salerno. Salerno and Paul Castellano at the time controlled the concrete unions in Manhattan and, when Donald Trump needed concrete, he received it from union leader John Cody who was linked to mob boss Castellano.
Rupert Murdoch was a client, and Cohn repeatedly pressured President Ronald Reagan to further Murdoch's interests. He is credited with introducing Trump and Murdoch, in the mid-1970s, marking the beginning of what was to be a long, pivotal association between the two.