Ibargüen was a legal aid lawyer in Hartford, Connecticut. He became the first executive director of the Connecticut Elections Commission, and practiced law for eight or nine years in Hartford. He joined the Times Mirror Company's "Hartford Courant" as senior vice president for finance and administration; moved to New York to work at New York "Newsday", where he stayed for 11 years. In 1995, he was named publisher of Knight Ridder's El Nuevo Herald and in 1998 he became publisher of The Miami Herald as well. In 2005, he became CEO of the John S. and James L. Knight Foundation.