 Lewin initiated a lawsuit against Yale University on behalf of Orthodox freshmen and sophomores who could not reside in co-educational dormitories on religious grounds.He brought lawsuits on behalf of Sabbath-observers who were discriminated against in private employment, on behalf of military chaplains who were denied the right to wear religiously motivated beards, and on behalf of Jewish prisoners who were denied kosher food.He was the attorney for the Satmar Kiryas Joel school for handicapped children in "Board of Education of Kiryas Joel Village School District v. Grumet", a case in defense of a law creating a special public school district for handicapped children in that community, which was heard by the Supreme Court in 1994.