Omar believed that law should serve the community and give effect to human rights and democracy. He put that belief forth when he was in practice because most of his clients were people who had been victimized by apartheid laws. He was the lawyer of numerous political prisoners and also acted as legal counsel for trade unions, civic and religious organizations.

 At the height of repression in the states of emergency, he played a key role, often at great personal sacrifice, in the flagship civic organization fighting against apartheid, the United Democratic Front. With the normalization of politics in 1990 he became the chairperson of the African National Congress in the Western Cape.

With the unbanning of the liberation movements in 1990, a vision for the new legal order based on justice, human rights and democracy was required. To this call Omar answered. He brought this vision and intellect to the University of the Western Cape and the Law Faculty when in 1990 he became the director of the Community Law Centre. Omar was the inspiration behind the Centre and worked tirelessly to establish it as a centre of research and advocacy on human rights and democracy.

 Under his directorship the Centre became a major contributor to policy formulation for the new constitutional order, focusing on the structure of the state, the electoral system, gender issues, children's rights, policing, and the transformation of the judiciary. With his colleagues at the Centre such Bulelani Ngcuka, Brigitte Mabandla, Zola Skweyiya, Prof Kader Asmal and Albie Sachs - he participated in the constitutional negotiations, charting the course towards the shaping of the new South Africa.

With the first democratic election in 1994 Omar was elected to Parliament. Befitting his role in the struggle for justice, he was appointed by President Mandela as Minister of Justice. On his shoulders thus fell the task of transforming a legal system that had propped up the perverse system of apartheid, into a system that embraced democracy, human rights and justice. Under Omar’s ministry, the administration of justice was transformed. The Constitutional Court was established, and the foundation was laid for the meaningful transformation of the judiciary. A single national prosecuting authority was formed. The Truth and Reconciliation Commission was created. Overall, the framework was developed for the transformation of the many facets and institutions of the administration of justice and democracy.