Pullen came to Washington from New Mexico in the late 1960s to attend the University of Washington. He earned a doctorate in chemistry in 1967 and taught for one year at the University of Idaho before returning to Washington. He got a job as a Boeing engineer and in 1972 he was elected to the State House of Representatives. In 1974, Pullen was elected to the State Senate, where he remained until he was elected to the King County Council in 1989.
The King County Council had been dominated by liberals of both parties from 1969 until 1989, when Pullen was elected with a new Republican majority. One thing that set Pullen apart from other conservative Republicans was his pro-union stance. When newly elected, he noted: "My base of support cuts across business and labor. I work closely with people." Pullen described himself as "a conservative who could work well with others." Metro King County Chair Pete von Reichbauer (R-Federal Way) , his fellow council member and friend, said, "What is unique about Kent is that even people who disagreed with him never found him disagreeable" (Seattle Post-Intelligencer).
Besides being an advocate for King County employees, children, the mentally ill, and victims of crime and domestic violence, Pullen was also a strong supporter of natural medicine. He spearheaded the establishment of the King County Natural Medicine Clinic in Kent, the region's first publicly funded natural medicine clinic.
Pullen had been planning to run for a fifth-year term on the Council representing the 9th Council District in 2005, and had already raised $300,000 (The Seattle Times). On April 14, 2003, Pullen died at age 60. At a memorial service held during a council session, president von Reichbauer spoke of his great humor, his integrity, and his unwavering adherence to principle.