HONOLULU -- University of Hawaii at Manoa Political Science professor Ira Rohter passed away Monday after more than 40 years on the job.

Rohter earned his Ph.D. in Political Science from Michigan State University in 1967 and joined UH Manoa in 1968, teaching political science.

Rohter was most widely known as co-chair for Hawaii Green Party, which he helped found in 1992. He was also on the board of the Hawaii Clean Elections Project and was the first vice president of the Hawaii Coalition Against Legalized Gambling.

Friends said Rohter died of an illness he contracted last week.

"I'm personally very saddened to hear of Ira's death," Hawaii Democratic Party Chair Brian Schatz said in a statement. "He was a progressive thinker who was passionate about making Hawaii a better place ... He understood the need for Hawaii to achieve economic and environmental sustainability and made it his mission to build a new generation of political activists."

Rohter also wrote a book, "A Green Hawaii: Sourcebook for Developmental Alternatives," which analyzes and gives solutions for sustainable development advocates in Hawaii and Pacific islands.