In the 1980s Hawkins joined the green movement. In 1988, he and Murray Bookchin founded the Left Green Network "as a radical alternative to U.S. Green liberals", based around the principles of social ecology and libertarian municipalism. In the early 1990s a press conference was held in Washington, D.C., that featured Charles Betz, Joni Whitmore, Hilda Mason, and Howie Hawkins to announce the formation of the Greens/Green Party USA. Later in December 1999, Mike Feinstein and Hawkins wrote the Plan for a Single National Green Party which was the plan to organize the ASGP and GPUSA into a single Green Party. A perennial candidate, Hawkins ran in multiple New York Senate and House races. In 2010 he surpassed the 50,000 vote requirement to stay on the ballot in the gubernatorial election and four years later he received enough to move the Green Party line to Row D as he had taken one-third more than the Working Families Party and twice as much as the Independence Party. However, in 2018 he lost 80,000 votes, but retained ballot access and was only lowered one row down to Row E.