Elliot was the main writer for DC comics during the Bronze and Modern ages of comics in the 1970s. He has started writing professionally in his teens. The first story he wrote for DC was for Green Lantern #87 (Dec 1971- Jan 1972).
Maggin ran for the U.S House of Representatives in New Hampshire's 2nd Congressional District but was defeated in the Democratic primary in 1984. In May 21, 2007, Maggin decided to run again for the 2008 Democratic Party nomination for California's 24 Congressional District. Although on October 1, 2008 he decided not to run. In an essay written the following day, Maggin cited financial reasons for his withdrawal.