Australian constitutionalism scored one of its greatest triumphs when the High Court invalidated the Communist Party Dissolution Act 1950 (Cth). That Act was designed to ban the Communist Party and affiliated bodies, and to restrict the civil liberties of persons declared by the Government to be dangerous or potentially dangerous communists. In other words, it potentially restricted the civil liberties of everyone. The High Court's decision, a celebrated victory for the rule of law, was followed by the defeat – remarkable at a time of anti-communist hysteria fanned by the Korean War – of a referendum to amend the Constitution to achieve the Government's objectives. Yet while a referendum defeat has lasting impact only in a negative sense, the Communist Party case lives on, and is as important a declaration of fundamental principles today as it was in 1951. As with all great constitutional decisions, the Communist Party case can only be understood in its historical and political context.

Before the ban

Robert Menzies' epochal general election victory of 10 December 1949 brought to office a Liberal-Country Party government committed to dissolving the Australian Communist Party.

This was not the first time a Menzies-led government had sought to ban the communists. Outlawing the Party had long been debated by the conservative parties, and unsuccessful measures had been taken against communists by the Lyons Government, in which John Latham was Attorney-General. But the Party had survived, assisted no doubt by the hardship of the Depression and the rise of fascism.