Born Martin Jezer and raised in the Bronx, he earned a history degree from Lafayette College.
He was a co-founding member of the Working Group on Electoral Democracy, and co-authored influential model legislation on campaign finance reform that has so far been adopted by Maine and Arizona.
He was editor of WIN magazine (Workshop In Nonviolence), from 1962-8, was a writer for Liberation News Service (LNS), and was active in the nuclear freeze movement, and the organic farming movement (he helped found the Natural Organic Farmers' Association).
In 1968 Jezer co-founded, with Verandah Porche, Richard Wizansky, and Ray Mungo, "Total Loss (Packer Corners) Farm" in Guilford, Vermont.
After moving to Guilford, he continued writing for WIN magazine, as well as Green Mountain Post, and the NOFA newsletter.