From 1972, Baum served as Parliamentary State Secretary at the Federal Ministry of the Interior under minister Hans-Dietrich Genscher, in the governments of ChancellorWilly Brandt and his successor Helmut Schmidt. From 1978 until 1982, Baum was Federal Minister of the Interior. During his time in office, he liberalized routine loyalty investigations of candidates for public‐service jobs, a controversial practice intended to control radical activity that had led to a profound and disruptive debate about the extent of democracy in West Germany. In 1981, with the backing of the Economics Minister Otto Graf Lambsdorff, he asked the German car industry to agree on goals to tighten emissions standards and cut fuel consumption on a voluntary basis. Following the collapse of the social–liberal coalition, Baum – alongside fellow FDP ministers Genscher, Lambsdorff, and Josef Ertl – resigned from the government on 18 September 1982.
Life after politics
Between 2000 and 2001, Baum and two other lawyers together represented about three-quarters of the Air France Flight 4590 crash victims' families. In May 2001, they reached a monetary settlement for compensation from Air France. According to people familiar with terms of the settlement, it was between $100 million and $125 million, an extraordinarily high sum for a plane-crash settlement in Europe at the time. From 2001 to 2003, Baum served as UN Special Rapporteur on the Situation of Human Rights in Sudan. In 2006, Baum presented a press freedom award to Berliner Zeitung for its resistance to an unpopular takeover by David Montgomery’s Mecom Group. In 2009, Germany's national railway company Deutsche Bahn commissioned Baum and former Justice Minister Herta Däubler-Gmelin with investigating allegations according to which the company had, in violation of privacy laws and corporate guidelines repeatedly and on a large scale compared personal data of its employees with those of suppliers, in a bid to uncover possible corruption. In 2016, Baum joined members of the Green Party, lawyers, a journalist and a doctor in bringing suits against Germany's 2009 antiterrorism law before the Federal Constitutional Court, arguing that covert surveillance, particularly in private homes and in the intimacy of bedrooms or bathrooms, could entangle innocent third parties. In a 6-to-2 vote, the court ruled that the antiterrorism laws were partly unconstitutional and demanded tighter control over surveillance.
Die Finanzkrise und ihre Folgen für die Bevölkerung. Anforderungen an einen verbesserten Verbraucherschutz, in: Robertson-von Trotha, Caroline Y. : Herausforderung Demokratie. Demokratisch, parlamentarisch, gut?, Baden-Baden 2011
Die Grundrechte im Spannungsverhältnis von Sicherheit und Freiheit, in: Robertson-von Trotha, Caroline Y. : 60 Jahre Grundgesetz. Interdisziplinäre Perspektiven, Baden-Baden 2009
