In 1963 Karabian graduated from the USC Law School and also obtained a Master of Science degree in Public Administration.
After college, Karabian was a Deputy District Attorney for the County of Los Angeles and entered into private practice with John H. Karns, in Monterey Park.
Karabian came to occupy a position of leadership among California Democrats and was eventually appointed the Assembly Majority Leader in 1971.
A progressive Democrat, Karabian authored bills that dealt with crime and the law, prison reform, education, civil rights, free speech, and the preservation of endangered species in California.
[4] In November 2010, Karabian pleaded no contest to a charge of "disturbing the peace" and was required to serve 40 hours of community service and three years' probation.