Professor Steinman is very active as a civil rights attorney while also serving as a professor at Santa Clara University School of Law. He has argued numerous times before the U.S. Supreme Court and was successful in three of these cases, including a landmark decision providing special education rights for millions of non-English-speaking and limited-English-speaking children. He is currently involved, as both a lawyer and community resident, in the operation of programs for the homeless in San Francisco. He also works with California Food Policy, advocating on issues of hunger and malnourishment.

Prior to joining the Santa Clara University School of Law faculty in 1972, Professor Steinman worked three years as a civil rights and poverty law attorney in San Francisco. He also served as a law clerk to U.S. District Court Judge Robert F. Peckham.