Cohen was first elected to his most recent position, by acclamation, in 2005, and left in 2015 succeeded by Chris Shelton.

Throughout his career, Cohen has chaired major contract negotiations in both the public and private sectors, at employers including Verizon and AT&T, as well as Cingular Wireless (now AT&T Mobility).

Cohen was one of the first to recognize changes in telecommunications through the convergence of video, voice and data technologies, and the need to unify unionized workers in these sectors.

As president, he built alliances and support for telecom workers around the world, including in Mexico, Taiwan, South Africa, Germany and other countries.

He is a founder of American Rights at Work, an co-founder of Jobs with Justice, and a member of the Democratic National Committee.